Answer:
Distillation
Explanation:
If the solute is a solid or a liquid with a boiling point at least 30 °C different from that of the solvent, you can use the technique of distillation.
The solvent will boil before the solid or a higher-boiling liquid.
A liquid solute with a lower boiling point than the solvent will boil off first, and then you can distill off the solvent.
Answer:
Distillation
Explanation:
Distillation is a process known long ago and according to some authors was created by the Alchemists at a time where Chemistry was not yet recognized as Science and was closely linked to religious precepts.
Basically the distillation process is a process of physical separation and is used to separate homogeneous mixtures from heating. To separate a solid-liquid type mixture we use simple distillation and to separate liquid-liquid mixtures we use fractional distillation.
Which is a substance that is made up of only one type of atom?
O compound
O element
solution
O mixture
Answer:
compound
Explanation:
An element is the type of substance that is made up of only one type of atom. It cannot be broken down further into other types of substances. Compounds and mixtures, on the other hand, contain more than one type of atom.
Explanation:The substance that is made up of only one type of atom is an element. An element is a pure substance that cannot be broken down into other types of substances. Each element is made up of just one type of atom. Examples of elements include Oxygen(O), Hydrogen(H), or any substance on the periodic table of elements. On the other hand, a compound is a substance that is made up of more than one type of atom bonded together. An example of this is water (H₂O), which consists of hydrogen and oxygen atoms. Lastly, a mixture is a combination of two or more elements or compounds which have not reacted to bond together, and each component in the mixture retains its original properties.
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What is the magnitude of the force of gravity between to 1000 kg cars which are separated by distance of 25. 0 km on an interstate highway? The force between the two cars will be what
Answer:
=1.068 ×10⁻¹³N
Explanation:
Force of gravity =Gm₁m₁/d² where G is the universal gravitation constant =G = 6.673 x 10-11 N m²/kg², m₁ and m₂ is the mass of object 1 and 2 respectively and d is the distance between them. First we change the distance into SI units i.e meters 25 km= 25000 m
F= (6.673 x 10⁻¹¹ N m²/kg²×1000 kg×1000 kg)/ (25000 m)²
=1.068 ×10⁻¹³N
Final answer:
The magnitude of the force of gravity between two 1000 kg cars separated by 25.0 km is 1.067 × 10^-6 Newtons, using Newton's law of universal gravitation.
Explanation:
To calculate the magnitude of the force of gravity between the two 1000 kg cars separated by 25.0 km, we can use Newton's law of universal gravitation, which is expressed by the formula:
F = G × (m1 × m2) / r2
Where:
F is the force of gravity between the two masses,G is the gravitational constant (6.674 × 10-11 N × (m/kg)2),m1 and m2 are the masses of the two objects, and r is the distance between the centers of the two masses.
Putting in the given values:
F = (6.674 × 10-11 N × (m/kg)2) × (1000 kg × 1000 kg) / (25,000 m)2 = 1.067 × 10-6 N
Thus, the force of gravity between the two cars is extremely small, 1.067 × 10-6 Newtons, which is consistent with the fact that the gravitational force is very weak at such distances and with masses as small as that of cars.
Recognizing the Properties of Water
Water has a "bent" geometry. Which explanation
does not explain why?
o Water's oxygen has unbonded electron pairs
that repel each other.
Water can form hydrogen bonds.
Electrons are evenly distributed in the water
molecule.
DO NE
Answer:
1. c
2.b
Explanation:
Schrodinger and Heisenberg developed an alternate theory about atomic nature that contradicted some of Bohr's model of the atom. How do changes resulting from new technology and evidence affect the reputation of the atomic theory?
Answer:
They don't affect the reputation of atomic theory at all.
Explanation:
Schrödinger and Heisenberg extended the model of the atom, as did Thompson, Rutherford, and Moseley before them.
Each model was based on the best available information at the time.
The availability of new information may require a new atomic model, but it doesn't destroy the reputation of older ones.
Answer: it did not affect the reputation of the atomic theory
Explanation:
Bohr only considered hydrogen and hydrogen-like atoms. Atoms with one electron. Schrödinger and Heisenberg extended it.
Every knowledge is science is alway built from previous knowledge. What you know to be right today might be proven wrong by someone else in the future. It doesn't mean you weren't right. So all scientists must keep an open mind, who knows, we might encounter aliens on earth in the future.
An ionic solid is placed in water. which information is described by the solubility product constant?
A. the amount of precipitate that will form from the ions
B.the temperature at which the solid and its ions reach equilibrium
C.the equilibrium between the solid and its ions in solution
Answer:
[tex]\boxed{\text{C. the equilibrium between the solid and its ions in solution}}[/tex]
Explanation:
[tex]\rm MX(s) $\, \rightleftharpoons \,$ M$^{+}$(aq) + $^{-}$(aq); $K_{\text{sp}}$ = [M$^{+}$][X$^{-}$]\\\\\text{$K_{\text{sp}}$ gives us information on}\\\\\boxed{\textbf{ the equilibrium between the solid and its ions in solution}}[/tex]
It tells us nothing about the amount of precipitate that will form or the temperature at which the equilibrium occurs.
Answer: Option (C) is the correct answer.
Explanation:
An ionic solid is defined as the solid in which atoms are chemically combined together due to transfer of electrons.
As all ionic substances are soluble in water. So, when an ionic solid is dissolved in water then it will dissociate into ions.
As a result, an equilibrium will be maintained between the solid and its ions into the solution.
For example, [tex]AB(s) \rightleftharpoons A^{+} + B^{-}[/tex]
[tex]K_{sp} = \frac{[A^{+}]}{[B^{+}]}[/tex]
where, [tex]K_{sp}[/tex] = solubility product
Thus, we can conclude that the information described by the solubility product constant is that there is equilibrium between the solid and its ions in solution.
An experiment is conducted to see if cats preferred skim milk or 2% milk. A cup of skim milk
was put out for 5 kittens and then measured how much the kittens drank over the course of a
day. Following a cup of 2% milk was purout for the skittens and then masured how much the
kittens drank over the course of a day. The same kittens were used and the milk was served at
the same temperature. It was discovered that the cats liked the 2% milk more than the skim
milk. What is the dependent variable in this experiment?
its milk you cant do the experiment with out it.
Answer:
the quantity of milk drank by the kittens
Explanation:
Dependent variables are the actual variables a researcher sets out to determine during the course of an experiment. In order words, dependent variables are variables that are measured during experiments whose values fluctuate with the change of other variables.
In this case, a change in the type of milk given to the kittens affected the quantity of milk drank by the animals.
The actual variable being measured in this experiment is the amount to milk drank by the kittens.
Hence, the dependent variable is the quantity of milk drank by the kittens.
How many moles of sodium chloride can react with 18.3 liters of fluorine gas at 1.2 atmospheres and 299 Kelvin?
Answer:
1.79 mol.
Explanation:
For the balanced reaction:2NaCl + F₂ → 2NaF + Cl₂.
It is clear that 2 mol of NaCl react with 1 mol of F₂ to produce 2 mol of NaF and 1 mol of Cl₂.
Firstly, we can get the no. of moles of F₂ gas using the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm (P = 1.2 atm).
V is the volume of the gas in L (V = 18.3 L).
n is the no. of moles of the gas in mol (n = ??? mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K),
T is the temperature of the gas in K (299 K).
∴ no. of moles of F₂ (n) = PV/RT = (1.2 atm)(18.3 L)/(0.0821 L.atm/mol.K)(299 K) = 0.895 mol.
Now, we can find the no. of moles of NaCl is needed to react with 0.895 mol of F₂:Using cross multiplication:
2 mol of NaCl is needed to react with → 1 mol of F₂, from stichiometry.
??? mol of NaCl is needed to react with → 0.895 mol of F₂.
∴ The no. of moles of NaCl needed = (2 mol)(0.895 mol)/(1 mol) = 1.79 mol.
In an exothermic reaction the bonding energy of the product is:
less than the reactants
same as the reactants
greater than the reactants
dependent upon the presence of a catalyst
Answer:
less than the reactants
Explanation:
Since the reaction is exhotermic, meaning that they have already released energy in the bonding, the product is releasing heat energy, and the reactants were not, so the products would have less bonding energy than the reactants.
How many grams of chloride are found in 72.03mg of magnesium chlorate?
Answer:
26.73 mg.
Explanation:
Firstly, we can calculate the no. of moles of magnesium chlorate (Mg(ClO₃)₂):no. of moles of magnesium chlorate (Mg(ClO₃)₂) = mass/molar mass = (72.03 mg)/(191.21 g/mol) = 0.377 mmol.
Every 1.0 mole of magnesium chlorate (Mg(ClO₃)₂) contains 2.0 moles of Cl.
∴ The no. of moles of Cl in magnesium chlorate (Mg(ClO₃)₂) = 2(0.377 mmol) = 0.754 mmol.
∴ The mass of Cl are found in 72.03 mg of magnesium chlorate (Mg(ClO₃)₂) = (no. of moles of Cl)(atomic mass of Cl) = (0.754 mmol)(35.453 g/mol) = 26.73 mg.
Which energy transformation occurs in the core of a nuclear reactor?
nuclear energy mechanical energy
nuclear energy thermal energy
thermal energy nuclear energy
mechanical energy nuclear energy
pls help there is a similar question on here I just need the answer dummed down
Nuclear energy to thermal energy
Answer:
option B
Explanation:
The correct answer is option B
A nuclear reactor is a device which is used to control and initiate the chain reaction. It is basically used in for power generation which can be used for many other purposes like electricity generation etc.
The energy transformation occurs in the core of a nuclear reactor is from nuclear energy to thermal energy.
0.66y = 0.9x + 0.48 If y has a value of 108.45 what is the value of x?
Answer:
y=108.45
0.66y=0.9x+0.48
0.66*108.45 =0.9x+0.48
71.577=0.9x+0.48
71.577-0.48=0.9x
71.097=0.9x
x=71.097/0.9
x=78.99667
Which of the following describes work?
holding a 1 kg mass for 1 hr
holding 1 kg mass
moving 1 m in 1 hr
lifting a 1 kg mass 1 m
Answer:
lifting a 1 kg mass 1 m.Explanation:
Work is the result of applying a force that manages to move a mass.
Thus, the work (mechanical work in this case because this is a mechanical force, not an electrical one) applied by a constant force is the product of the force times the distance that the object is moved.
Also, you can calculate the mechanical work as the difference in the mechanical energy between the initial and the final stages of the event where the force was applied.
Let's see each choice:
a) Holding a mass for 1 hr: since no translation is involved, displacement is and the work is zero.
b) Holding 1 kg mass: again, no motion is involved, so there is no work.
c) Moving 1 m in 1 hr: there is not force involved in this statement, so there is not work.
d) lifting a 1 kg mass 1 m: this, indeed, describes a situation where work results from applying a lifting force to move a mass 1 m up.
In this case, such work is equal to the change in the potential energy of the mass: mgΔh = 1kg × 9.8m/s² × 1 m = 9.8 joules.
Answer:
D lifting a 1 kg mass 1 m
Explanation:
Took the test and got 100%
if you have 560 grams of magnesium. what mass of magnesium oxide will be produced?
Answer:
=933.3 grams
Explanation:
Magnesium reacts with oxygen producing magnesium oxide according to the following equation.
2Mg₍s₎ + O₂₍g₎→ 2MgO₍s₎
From the above equation, 2 moles of Magnesium produces 2 moles of magnesium oxide. Therefore the ratio of magnesium to magnesium oxide produced is 1:1
1 mole of magnesium oxide has a mass of: 24+16 =40 grams
560 grams of magnesium=560/24 moles
=70/3 moles.
Since the ratio is 1:1 the reaction produces 70/3 moles of magnesium oxide.
70/3 moles of MgO= 70/3 moles× 40 grams
=933.3 grams
Answer:
Here's what I get.
Explanation:
[tex]\begin{array}{lcccc}\textbf{(a)} \qquad \text{Na} & \text{reacts with} & \text{ diatomic chlorine}& \text{to form} & \text{sodium chloride}\\\textbf{(b)}\qquad \text{Na} & + & \text{Cl}_{2} & \longrightarrow \, & \text{NaCl}\\\textbf{(c)}\qquad \text{2Na}& + & \text{Cl}_{2} & \longrightarrow \, & \text{2NaCl}\\\end{array}[/tex]
(d) Mass of chlorine
(i) We know we will need an equation with masses and molar masses, so let’s gather all the information in one place.
M_r: 70.91 58.44
2Na + Cl₂ ⟶ 2NaCl
m/g: 117
(ii) Calculate the moles of NaCl
[tex]\text{Moles of NaCl} = \text{117 g NaCl} \times \dfrac{\text{1 mol NaCl}}{\text{58.44 g NaCl }} = \text{2.002 mol NaCl }[/tex]
(iii) Calculate the moles of Cl₂
The molar ratio is (1 mol Cl₂ /2 mol NaCl)
[tex]\text{Moles of Cl$_{2}$}= \text{2.002 mol NaCl} \times \dfrac{\text{1 mol Cl$_{2}$}}{\text{2 mol NaCl}} = \text{1.001 mol Cl$_{2}$}[/tex]
(iv) Calculate the mass of Cl₂
[tex]\text{Mass of Cl$_{2}$} = \text{1.001 mol Cl$_{2}$} \times \dfrac{\text{70.91 g Cl$_{2}$}}{\text{1 mol Cl$_{2}$}} = \text{71.0 g Cl$_{2}$}\\\\\text{The mass of chlorine needed is } \boxed{\textbf{71.0 g Cl$_{2}$}}[/tex]
Gravity is a force that helps to hold the universe together.
Final answer:
Gravity is an ever-present, attractive force that holds together the Universe, from maintaining our footing on Earth to influencing the motions of galaxies and beyond. It is defined by Newton's law of gravitation and further explored in the theory of general relativity.
Explanation:
Gravity is a fundamental force of nature that is always attractive, causing objects with mass to be pulled toward each other. Even though gravity is the weakest of the four fundamental forces, it plays a crucial role in structuring the Universe. From binding us to the surface of Earth to keeping planets in orbit around the Sun, and even holding galaxies together, gravity is essential for the existence and movement of celestial bodies. Newton's universal law of gravitation states that gravitational force is directly proportional to the masses of the objects involved and inversely proportional to the square of the distance between their centers. On a cosmic scale, gravity is the dominant force and is important for understanding the interactions of matter in space and time. Additionally, in the realm of general relativity, gravity is responsible for curving space and altering the flow of time near massive bodies like stars.
what is geography and importance of geography
Answer:
Meaning; Geography is a focus within the curriculum for understanding and resolving issues about the environment and sustainable development. It is also an important link between the natural and social sciences. As pupils study geography, they encounter different societies and cultures.
Importance; Geography is important because it contributes to our knowledge of the world and its phenomena. But, it also has an amazing practical side. For economists and managers, some types of engineering, farmers, architects, geopoliticians, generals and some knowledge of Geography is extremely important.
brainiest plz
Explanation:
Answer:
Geography is the physical features of places and landmarks around the globe.
Explanation:
Geography is important because it marks where places are, and geography can help you find you way.
1.74 A flask contains a 30.0 mL sample of acetone (nail polish remover) that weighs 23.6 grams.
What is the density of the acetone?
Answer:
ρ = 0.787 g/cm³
Explanation:
1 mL= 1 cm³
30.0 mL= 30 cm³
Density = mass/volume
The mass provided in the question= 23.6 grams
Volume= 30.0 cm³
Thus density= 23.6 grams/ 30.0 cm³
=0.787 g/cm³
If required in kg/ m³ the density will be calculated as follows.
There are 1000 g in 1 kg thus the density =
=0.787 g/cm³ ×1000
=787 kg/m³
When determining the shape of a molecule, it is important to draw a Lewis Dot structure first in order to see the total number of...?
A. electrons within the molecule
B. bonding and unshared pairs around central atom
C. unshared pair within the molecule
(PLEASE HELP I REALLY NEED IT )
Answer : The correct option is, (B) bonding and unshared pairs around central atom.
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule.
When we are determining the shape of a molecule then it is important to draw a Lewis-dot structure and for drawing a Lewis-dot structure we should know that how many total number of valance electrons present in a given compound or a molecule.
For example:
The given molecule is, [tex]H_2CO_3[/tex]
As we know that hydrogen has '1' valence electrons, carbon has '4' valance electrons and oxygen has '6' valence electron.
Therefore, the total number of valence electrons in [tex]H_2CO_3[/tex] = 2 + 4 + 18 = 24
Now we have to determine the hybridization of carbon in [tex]H_2CO_3[/tex]
Number of bond pairs = 3
Number of lone pairs = 0
Number of atomic orbitals around carbon atom = 3 + 0 = 3
So, hybridization will be [tex]sp^2[/tex] and the shape is, trigonal planar.
Hence, it is important to draw a Lewis Dot structure first in order to see the total number of bonding and unshared pairs around central atom.
WHICH OF THE FOLLOWING WILL RESULT FROM INCREASING THE TEMPERATURE OF A GAS - APEX
Answer:
it will stay a gas
Explanation:
by heating up a gas you are making sure the gas stays a gas
What part of Dalton’s atomic theory was later proved to be incorrect?
Answer:
D
Explanation:
It was later identified that atoms of the same element can be different. This is mostly seen in elements with different isotopes. An example is carbon-14 and carbon-12 that have different masses due to differences in neutrons numbers in their nuclei.
Atoms are also divisible into subatomic particles. Today, atoms can be smashed apart into neutrons, protons and electrons particles. This also occurs naturally in radioactive decay.
It was later identified that atoms of the same element can be different. This is mostly seen in elements with different isotopes. The correct option is D.
Thus, An example is carbon-14 and carbon-12 that have different masses due to differences in neutrons numbers in their nuclei.
Atoms are also divisible into subatomic particles. Today, atoms can be smashed apart into neutrons, protons and electrons particles. This also occurs naturally in radioactive decay.
John Dalton, an English physicist and chemist, proposed the atomic hypothesis in 1808 as a scientific theory about the composition of matter. It claimed that tiny, indivisible particles called "atoms" make up all substance.
According to Dalton's atomic theory, atoms, which are indestructible and indivisible building blocks, make up all substances. Unlike other elements, which have atoms of different sizes and weights, an element's atoms have all the same size and mass.
Thus, It was later identified that atoms of the same element can be different. This is mostly seen in elements with different isotopes. The correct option is D.
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Which substance is a compound iron or nitrogen oxide
Answer:
Nitrogen oxide is compound.
Explanation:
Compound is defined as chemical substance made up two or more than two different elements. For example : NaOH is the compound made up of 1 sodium atom, 1 oxygen atom and 1 hydrogen atom.
Now, according to the question, out iron and nitrogen oxide. Nitrogen dioxide (NO)is a compound because its made up of one nitrogen atom and 1 oxygen atom.
Where as iron is not a compound because it is just composed of iron atoms only.
Which are causes of mechanical weathering? Check all that apply.
O
acid rain
O plant growth
O animal actions
O carbon dioxide
O pressure release
Answer: Plant growth, animal actions and pressure release
Explanation:
The weathering is a process of disintegration of rocks into small pieces and sediments. This is caused by chemical or physical agents.
Mechanical weathering is also called as physical weathering. It is caused by the physical activities on the surface of rocks. The following are the examples of mechanical weathering.
1. Plant growth: The plants which grows over the surface of rocks, their roots may penetrate the rocks which causes the disintegration or rocks.
2. Animal actions: The animals may exert their pressure over the surface of rocks. They may create burrows like rat or mice inside the rocks.
3. Pressure release: The rock which was under pressure, instantly if pressure released, the structure of rock will become unstable, this may lead to the disintegration of the rock.
Chains of amino acids make which can join together to make a
Answer:
Polypeptide chain
What is the correct name for the compound CoCl3?
a) cobalt(I) chloride
B) cobalt(I) chlorate
C) cobalt(II) chlorate
D) cobalt(III) chloride
Answer:
D) Cobalt (III) chloride.
Explanation:
It is an unstable compound in which the cobalt atoms have a formal charge of +3.
It could be stable but at very low temperatures, while at high temperatures it is found as a gas.
I hope this answer helps you.
Cobalt(III) chloride, often known as cobaltic chloride, is an elusive and unstable cobalt and chlorine chemical with the formula CoCl₃. The cobalt atoms in this combination have a formal charge of +3. Here the correct option is D.
Due to its special characteristics, cobalt chloride (CoCl₃) is a chemical substance that is frequently utilized in scientific study. It is a crystalline solid that is pinkish-red and soluble in ethanol and water. Cobalt ions, which are necessary for the growth and development of both plants and animals, can be found in cobalt chloride.
Cobalt(III) chloride, often known as cobaltic chloride, is an elusive and brittle cobalt and chlorine chemical with the formula CoCl₃. The cobalt atoms in this combination have a formal charge of +3.
Thus the correct option is D.
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. Write the following isotope in nuclide notation (e.g., “ ”): copper-70
Answer:
[tex]{\boxed{\text{$_{29}^{70}${Cu}}}[/tex]
Explanation:
The atomic number (Z) of copper is 29 and this isotope has an atomic mass (A) of 70.
The general symbol for an isotope E is [tex]_{Z}^{A}\text{E}[/tex].
The atomic number is a left subscript, and the atomic mass is a left superscript.
[tex]\rm {\text{The nuclide notation for copper-70 is }}{\boxed{\textbf{$_{29}^{70}${Cu}}}[/tex]
In a molecule of two electron dot structures describe the bond equally well?
Answer:
The correct answer for this is: [tex] O _ 3 [/tex].
Explanation:
It is in a molecule of O3 that the two electron dot structures describe the bond equally well.
The [tex] O _ 3 [/tex] molecule is called trioxygen and more commonly known as ozone. It is a pale blue colored gas having a strong pungent smell.
This inorganic molecule is widely used in the oxidation process in the industries as well as consumer application.
2. Iron reacts with oxygen gas according to the following equation:
4 Fe + 3 O2 -> 2 Fe2O3
If 2 moles of oxygen gas is used in the reaction,
a) how many moles of iron, Fe, will be required?
(b) how many moles of iron(III) oxide, Fe2O3, will be produced?
3. Potassium sulfate can be prepared by the reaction between dilute sulfuric acid
and potassium carbonate.
H2SO4 + K2CO3 → K2SO4 + CO2 + H2O
Calculate the mass of potassium sulfate that can be prepared from 3.45 g of
potassium carbonate.
4. The reaction between zinc and aqueous chromium(III) nitrate can be represented
by the following equation:
3 Zn (s) + 2 Cr(NO3)3 → 3 Zn(NO3)2 + 2 Cr
If 16.25 g of zinc is used to react with chromium(III) nitrate, calculate the mass of
chromium that will be produced.
5. Ethane, CzHe, burns in oxygen gas according to the following equation:
2 C2He + 7 02 – 4 CO2 + 6H20
If 72 dm of ethane gas is completely burnt in oxygen, calculate
(a) the volume of carbon dioxide, measured at room temperature and
pressure produced.
(b) the volume of oxygen, measured at room temperature and pressure
required
Answer:
2. a) 2.67 mol.
b) 1.33 mol.
3. 4.35 g.
4. 8.67 g.
5. a) 143.86 L.
b) 251.75 L.
Explanation:
2. Iron reacts with oxygen gas according to the following equation:
4Fe + 3O₂ → 2Fe₂O₃ , If 2 moles of oxygen gas is used in the reaction,
Fe reacts with O₂ according to the balanced equation:4Fe + 3O₂ → 2Fe₂O₃,
It is clear that 4 mole of Fe react with 3 mole of O₂ to produce 2 moles of Fe₂O₃.
a) how many moles of iron, Fe, will be required?
using cross multiplication:
3 mol of O₂ require → 4 mol of Fe, from the stichiometry.
2 mol of O₂ require → ??? mol of Fe.
∴ The no. of moles of of Fe are required = (2 mol)(4mol)/(3 mol) = 2.67 mol.
(b) how many moles of iron(III) oxide, Fe₂O₃, will be produced?
using cross multiplication:
3 mol of O₂ produce → 2 mol of Fe₂O₃, from the stichiometry.
2 mol of O₂ require → ??? mol of Fe₂O₃.
∴ The no. of moles of of Fe₂O₃ are produced = (2 mol)(2 mol)/(3 mol) = 1.33 mol.
3. Potassium sulfate can be prepared by the reaction between dilute sulfuric acid and potassium carbonate.
H₂SO₄ + K₂CO₃ → K₂SO₄ + CO₂ + H₂O,
Calculate the mass of potassium sulfate that can be prepared from 3.45 g of potassium carbonate.
H₂SO₄ reacts with K₂CO₃ according to the balanced equation:H₂SO₄ + K₂CO₃ → K₂SO₄ + CO₂ + H₂O,
It is clear that 1 mole of H₂SO₄ reacts with 1 mole of K₂CO₃ to produce 1 mole of K₂SO₄, 1 mole of CO₂ and 1 mole of H₂O.
Firstly, we need to calculate the no. of moles of 3.45 g of K₂CO₃:
no. of moles of K₂CO₃ = mass/molar mass = (3.45 g)/(138.205 g/mol) = 0.025 mol.
using cross multiplication:
1 mol of K₂CO₃ produce → 1 mol of K₂SO₄, from the stichiometry.
∴ 0.025 mol of K₂CO₃ produce → 0.025 mol of K₂SO₄.
∴ The mass of K₂SO₄ are produced = (no. of moles of K₂SO₄ produced)(molar mass of K₂SO₄) = (0.025 mol)(174.259 g/mol) = 4.35 g.
4. The reaction between zinc and aqueous chromium(III) nitrate can be represented by the following equation:
3Zn(s) + 2Cr(NO₃)₃ → 3Zn(NO₃)₂ + 2Cr
If 16.25 g of zinc is used to react with chromium(III) nitrate, calculate the mass of chromium that will be produced.
Zn reacts with Cr(NO₃)₃ according to the balanced equation:3Zn(s) + 2Cr(NO₃)₃ → 3Zn(NO₃)₂ + 2Cr ,
It is clear that 3 mole of Zn reacts with 2 mole of Cr(NO₃)₃ to produce 3 mole of Zn(NO₃)₂ and 2 mole of Cr.
Firstly, we need to calculate the no. of moles of 16.25 g of Zn:
no. of moles of Zn = mass/atomic mass = (16.25 g)/(65.38 g/mol) = 0.25 mol.
using cross multiplication:
3 mol of Zn produce → 2 mol of Cr, from the stichiometry.
∴ 0.25 mol of Zn produce → ??? mol of Cr.
∴ The no. of moles of Cr are produced = (2 mol)(0.25 mol)/(3 mol) = 0.167 mol.
∴ The mass of Cr are produced = (no. of moles of Cr produced)(atomic mass of Cr) = (0.167 mol)(51.9961 g/mol) = 8.67 g.
5. Ethane, C₂H₆, burns in oxygen gas according to the following equation:
2 C₂H₆ + 7 O₂ → 4 CO₂ + 6H₂O,
If 72 dm³ of ethane gas is completely burnt in oxygen, calculate
(a) the volume of carbon dioxide, measured at room temperature and
pressure produced.
Firstly, we can calculate the no. of moles of 72 dm³ ethane at room temperature and pressure using the general law of ideal gas: PV = nRT.
where, P is the pressure of the gas in atm (P = 1.0 atm).
V is the volume of the gas in L (V = 72.0 dm³ = 72.0 L).
n is the no. of moles of the gas in mol (n = ??? mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K),
T is the temperature of the gas in K (T = 298.0 K, room temperature).
∴ n of ethane = PV/RT = (1.0 atm)(72.0 L)/(0.0821 L.atm/mol.K)(298.0 K) = 2.94 mol.
So, we can calculate the no. of moles of CO₂:
using cross multiplication:
2 mol of C₂H₆ produce → 4 mol of CO₂, from the stichiometry.
∴ 2.94 mol of C₂H₆ produce → ??? mol of CO₂.
∴ The no. of moles of CO₂ are produced = (2.94 mol)(4.0 mol)/(2 mol) = 5.88 mol.
∴ The volume of moles of CO₂ are produced = nRT/P = (5.88 mol)(0.0821 L.atm/mol.K)(298.0 K)/(1.0 atm) = 143.86 L.
(b) the volume of oxygen, measured at room temperature and pressure
required.
using cross multiplication:
2 mol of C₂H₆ require → 7 mol of O₂, from the stichiometry.
∴ 2.94 mol of C₂H₆ require → ??? mol of O₂.
∴ The no. of moles of O₂ are required = (2.94 mol)(7.0 mol)/(2 mol) = 10.29 mol.
∴ The volume of moles of O₂ are produced = nRT/P = (10.29 mol)(0.0821 L.atm/mol.K)(298.0 K)/(1.0 atm) = 251.75 L.
The ideal gas constant, R has several different values that could be used. Which quantity causes these differences?
pressure
temperature
volume
moles
Answer: Pressure
Explanation:
The pressure is sometimes measured in different units
Answer:
pressure
Explanation:
The different values of R are as follows:
R = 0.0821 liter•atm/mol•K.
R = 62.3637 L•Torr/mol•K or L•mmHg/mol•K.
Here the different units of pressure are atm, Torr and mmHg.
The unit of volume, temperature and moles are Liter (L), Kelvin (K) and mol respectively.
When different values of Pressure are used and expressed in different units that cause a change in the value of R.
PLEASE HELP ASAP
which of the following are examples of chemical changes
-silver tarnishes
- a sheet of copper is pounded into the shape of a bowl
- barium melts at 725° C
- Hydrogen reacts with oxygen to form water
Answer: Hydrogen reacts with oxygen to form water
Explanation: Chemical changes are those which changes the identity of the chemical nature of any substance.
Thus out of the given options , the correct one is the formation of the water molecule when hydrogen reacts with oxygen as it is changing the identity of hydrogen and oxygen atoms to form a molecule of water.
The rest of the three options belongs to the category of the physical changes in which the chemical nature of any substance has not been changed but only the properties which an be easily observed can be changed.
Which statements describe polyatomic ions? Check all that apply.
Polyatomic ions have many charges.
Polyatomic ions have one overall charge.
Polyatomic ions repel other ions to form ionic bonds.
Polyatomic ions attract other ions to form ionic bonds.
Polyatomic ions are made up of only one type of atom.
Polyatomic ions are made up of two or more types of atoms.
Answer:
B, D, F
Explanation:
The polyatomic ion statements are
- Polyatomic ions have one overall charge.
- Polyatomic ions are made up of two or more types of atoms.
- Polyatomic ions are ions composed of two or more atoms that are covalently bonded together and carry an overall electrical charge due to the loss or gain of electrons.
- They have one overall charge because the entire molecule gains or loses electrons to become an ion.
- Polyatomic ions are composed of two or more types of atoms, usually including both nonmetals and sometimes a central metal atom.
Complete Question:
Which statements describe polyatomic ions? Check all that apply.
- Polyatomic ions have many charges.
- Polyatomic ions have one overall charge.
- Polyatomic ions repel other ions to form ionic bonds.
- Polyatomic ions attract other ions to form ionic bonds.
- Polyatomic ions are made up of only one type of atom.
- Polyatomic ions are made up of two or more types of atoms.
Carbon (C): 1sH2sI2pJ H = I = J =
Answer:H=2 I=2 J=2
Explanation:
Answer:
H= 2
I= 2
J=2
Explanation:
Just did this answer on ingenuity. :)