Answer: [tex]5.2\times 10^{22} atoms[/tex] of iodine are present in 12.75 grams of [tex]CaI_2[/tex].
Explanation:
[tex]moles=\frac{\text{given mass of the compound}}{\text{molar mass of the compound}}[/tex]
Moles of Calcium iodide :
Moles of [tex]CaI_2=\frac{12.75 g}{293.8 g/mol}=0.0433 moles[/tex]
number of molecules of [tex]CaI_2[/tex] in 0.0433 moles = [tex]N_A\times \text{number of moles}=6.022\times 10^{23}\times 0.0433=2.60\times 10^{22} molecules [/tex]
In one molecule of calcium iodide there are two iodine atoms, then number of iodine atoms in [tex]2.60\times 10^{22} molecules [/tex] of [tex]CaI_2[/tex]
[tex]2\times 2.60\times 10^{22} atoms=5.2\times 10^{22} atoms[/tex]
Hence, there are [tex]5.2\times 10^{22} atoms[/tex] of iodine are present in 12.75 grams of [tex]CaI_2[/tex].
which of these is a trace fossil : shrimp burrow, seashell, dinosaur egg, shark tooth
Shrimp burrow which is one of the examples of trace fossils.
Answer:
Option (1)
Explanation:
Trace fossils are defined as those traces such as the impressions and signs of ancient remains of an organism, that are found over relatively softer sediment.
These play a very important role in the field of paleontology as it provides information about the ancient organism that lived in the past in a particular location.
Some of the examples of trace fossils are track and trails, burrows, footprints, cast and mold.
Shrimp burrows are an example of trace fossils, which are made by the marine organisms named shrimps, that are usually found at the bottom of the ocean.
Thus, the correct answer is option (1).
NEED HELP ASAPPPPP!
A natural gas stove transforms R energy into P energy.
What do R and P most likely represent?
A.) R represents chemical energy, P represents thermal energy
B.) R represents thermal energy, P represents chemical energy
C.) R represents potential energy, K represents electrical energy
D.) R represents electrical energy, K represents potential energy
Which field would modify a cow's DNA to produce more milk?
The answer would be D.) Genetic Engineering
what types of charge does a
A 0.630 gram sample of a metal, M, reacts completely with sulfuric acid according to:A volume of 291 mL of hydrogen is collected over water; the water level in the collecting vessel is the same as the outside level. Atmospheric pressure is 756.0 Torr and the temperature is 25 °C. The vapor pressure of water at various temperatures can be found in this table. Calculate the molar mass of the metal.
Answer:
55.0 g/mol
Step-by-step explanation:
Step 1. Partial pressure of hydrogen
You are collecting the gas over water, so
[tex]p_{\text{atm}} = p_{\text{H}_{2}} + p_{\text{H}_{2}\text{O}}[/tex]
[tex]p_{\text{H}_{2}} = p_{\text{atm}} - p_{\text{H}_{2}\text{O}}[/tex]
[tex]p_{\text{atm}} = \text{756.0 Torr}[/tex]
At 25 °C,[tex]p_{\text{H}_{2}\text{O}} = \text{23.8 Torr}[/tex]
[tex]p_{\text{H}_{2}} = \text{756.0 Torr} - \text{23.8 Torr} = \text{732.2 Torr}[/tex]
===============
Step 2. Moles of H₂
We can use the Ideal Gas Law.
pV = nRT Divide both sides by RT
n = (pV)/(RT)
p = 732.2 Torr Convert to atmospheres
p = 732.2/760
p = 0.9634 atm
V = 291 mL Convert to litres
V = 0.291 L
R = 0.082 06 L·atm·K⁻¹mol⁻¹
T = 25 °C Convert to kelvins
T = (25 + 273.15 ) K = 298.15 K
n = (0.9632 × 0.291)/(0.082 06 × 298.15)
n = 0.2804/24.47
n = 0.011 46 mol
===============
Step 3. Moles of metal
The partial chemical equation is
M + H₂SO₄ ⟶ H₂ + …
The molar ratio of M:H₂ is 1 mol M:1 mol H₂.
Moles of M = 0.011 46× 1/1
Moles of M = 0.011 46 mol M
===============
Step 4. Atomic mass of M
Atomic mass = mass of M/moles of M
Atomic mass = 0.630/0.011 46
Atomic mass = 55.0 g/mol
which is the empirical formula for hydrogen peroxide
H2O2 i think this is it
H2O2 i believe is the answer sorry if im wrong
What is the mole ratio of D to A in the generic chemical reaction? 2A+B >C+3D
Answer: The mole ratio of D : A is 3 : 2.
Explanation: Mole ratio for a chemical reaction is the ratio of their respective stoichiometric numbers or the ratio of their moles in a chemical reaction.
For a given chemical reaction:
[tex]2A+B\rightarrow C+3D[/tex]
By stoichiometry,
2 moles of A is reacting with 1 mole of B to produce 1 mole of C and 3 moles of D.
So, Mole ratio of D is to A will be 3 : 2
Answer: D : A is 3 : 2.
Explanation:
The law of definite proportion is being used here. The law states that a given compound always has the same proportion of its constituent elements by mass. The numbers written in the equation are used to balance it, which is an important part whilst determining the mole ratio
Keeping in mind law:
2a + b => c + 3d
Using the concept of stoichiometry coefficients of d and a
So the ratio of d:a is 3:2
Is fluorine a metal or a nonmetal? How many valence electrons does a fluorine atom have?
Answer: The given element is non-metal and the number of valence electrons are 7
Explanation:
There are 2 types of elements in the periodic table:
Metals are the elements which have a tendency to loose electrons and thus they form cations. Example: Sodium will loose 1 electron to form [tex]Na^+[/tex] ion.Non-metals are the elements which have a tendency to gain electrons and thus they form anions. Example: Chlorine will gain 1 electron to form [tex]Cl^-[/tex] ion.Valence electrons are defined as the electrons which are present in the outermost shell of an atom. Outermost shell has the highest value of 'n' that is principal quantum number.
We are given:
Fluorine is the 9th element of the periodic table having electronic configuration of [tex]1s^22s^22p^5[/tex]
This element will gain 1 electron to form [tex]F^-[/tex] ion
Number of valence electron in fluorine element = 2 + 5 = 7
Hence, the given element is non-metal and the number of valence electrons are 7
Which of the following is not a correct chemical equation for a double displacement reaction? (2 points) 2RbNO3 + BeF2yields Be(NO3)2 + 2RbF CaCl + LiCO3yields CaCO3 + LiCl Na3PO4 + 3KOH yields 3NaOH + K3PO4 2MgI2 + Mn(SO3)2yields 2MgSO3 + MnI4
Answer: [tex]2MgI_2+Mn(SO_3)_2\rightarrow 2MgSO_3+MnI_4[/tex]
Explanation:
Double displacement reaction: it is a chemical reaction in which the reactants exchanges their ions to form new compounds as a products.
[tex]AB+CD\rightarrow AD+CB[/tex]
All the reaction are example of double displacement reaction beside reaction where magnesium iodide is reacting with manganese(II) sulfate to give magnesium sulfate and manganese(IV) iodide .
[tex]2MgI_2+Mn(SO_3)_2\rightarrow 2MgSO_3+MnI_4[/tex]
In this reaction , charge on manganese have changed from 2+ to 4+. Manganese in getting oxidized. Example of an oxidation reaction. Hence, this reaction is not an example of double displacement reaction.
what is the difference between potassium 39, 41, and 40
Answer to the last part 48 part D!!!
Answer :
In general trend,
The size of the element increases as we go down in a same group.
And the electronegativity of the element decreases as we go down in a same group.
For example : The two elements Magnesium and Calcium in a same group number 2.
The size of calcium is greater than the magnesium because as we go down in a group the atomic radius increases and the size also increases. And the electronegativity of calcium is less than the magnesium because as we go down in a group the electronegativity decreases.
which two units commonly measure heat? pick two answers
a. watts
b. joules
c. calories
d. amperes
Identify what type of reaction is below. Also, determine what coefficients that would balance the chemical equation. ___ C4H10 + ___O2 → ___ CO2 + ___H2O
This is a combustion reaction because it is being combined with oxygen. Then to balance you will put the number of carbons you have or 4 in front of the CO2 and then same with H2. Then you will add up the oxygen and divide it by two to get. 1, (13/2), 4, 5
When is it appropriate to use models?
Models should be used only when explaining submicroscopic matter.
Models should be used to complicate the phenomena so it is more realistic. Model should be used once they are completely accurate for all the scientific data. Models should be used when needed to explain or predict data being represented.
your answer should be the last one: models should be used when needed to explain or predict data being represented.
hope this helps :)
A sample of nitrogen gas occupies 2.49 L at 19.5°C. The volume of the container changes at constant pressure to 4.29 L. What temperature (in°C) must the gas be to attain this volume?
Answer : The final temperature of the gas must be [tex]33.596^oC[/tex]
Solution : Given,
Initial volume of gas = 2.49 L
Final volume of gas = 4.29 L
Initial temperature of gas = [tex]19.5^oC[/tex]
According to the Charles' law, the volume of gas is directly proportional to the temperature of the gas at constant pressure.
[tex]V\propto T[/tex]
[tex]\frac{V_1}{V_2}=\frac{T_1}{T_2}[/tex]
Now put all the given values in this formula, we get the final temperature of the gas.
[tex]\frac{2.49L}{4.29L}=\frac{19.5^oC}{T_2}[/tex]
By rearranging the term, we get
[tex]T_2==33.596^oC[/tex]
Therefore, the final temperature of the gas must be [tex]33.596^oC[/tex]
which has a higher temperature?
A.a small cup of boiling hot water B. a large pot of boiling hot water C. they have the same temperature
This answer varies. It would be B. because it's a large pot of water ( made of steel, iron or whatever ) and since it's a good conductor, it would transfer heat energy to the water and keep it warm.
It may not be A. because it's a small cup and the more molecules or matter it has the more thermal energy so it likely they would both be the same temperature.
Hope that helps.
What do R and P most likely represent?
A.) R represents chemical energy, P represents thermal energy
B.) R represents thermal energy, P represents chemical energy
C.) R represents potential energy, K represents electrical energy
D.) R represents electrical energy, K represents potential energy
Answer is: A.) R represents chemical energy, P represents thermal energy.
A natural gas stove transforms R energy into P energy.
For example methane is natural gas.
Balanced chemical reaction of methane combustion:
CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g) ΔH = -802.3 kJ.
This is exothermic reaction, energy is released in form of heat.
The law of conservation of energy states that the total energy of an isolated system remains constant; energy can neither be created nor destroyed; it can only be transformed or transferred from one form to another.
how does the ph of hydrochloric acid change when copper oxide is graduallt added to hydrochloric acid until excess?
does it increase? decrease?
Copper does not react with HCl acid, but copper oxide does react. A metal-acid reaction is always a redox reaction. Since copper has a higher reduction potential than hydrogen, it does not react with non-oxidising acids like HCl or dil.H2SO4.
match the bond its formula
1.___ NaCl . a.covalent
2.___CO2 . b.metallic
3.___ZnCu . c. ionic
1. c. ionic___ NaCl .
2. a.covalent___CO2
3. b.metallic ___ZnCu
The Lewis dot model of a metal atom has two dots. Which of the following is true about the atom?
It is most likely to form covalent bonds.
It has two electrons in the innermost energy level.
It requires six other atoms to form a stable compound.
It is present in the second group of the periodic table.
Answer : the statement that is true about the atom is It is present in the second group of the periodic table.
Explanation :
The Lewis dot model shows the number of valence electrons present in the atom.
Since the given metal has 2 dots, it indicates that the metal atom must have 2 electrons in its outermost shell.
Therefore option 2 : It has two electrons in the innermost energy level, is wrong because it contains 2 electrons in the outermost energy level
Option 1 : It is most likely to form covalent bonds is also wrong because a metal atom always forms ionic bond
Option 3 : It requires six other atoms to form a stable compound, is also wrong as the metal can form a stable compound by donating its 2 electrons to a non metal.
On periodic table, representative elements are arranged in groups based on their valence electrons. Therefore by knowing the outermost electrons, we can predict the group in which the element can be categorized.
Since the given metal atom contains 2 electrons, it must be present is second group.
Therefore the statement that is true about the atom is It is present in the second group of the periodic table.
What is the mass of 2.80 grams of H2O
The mass of 2.80 grams of h2o is 18.02 amu I believe
In a butane lighter, 9.7 g of butane combines with 34.7 g of oxygen to form 29.3 g carbon dioxide and how many grams of water
The balanced reaction is:
2C4H10 + 13O2 ---> 8CO2 + 10H2O
9.7g + 34.7g = 29.3g + -------g
Total mass of reactants = total mass of products
44.4g = 29.3 + g of water
44.4 - 29.3 = g of water
15.1g = g of water
grams of water produced here is 15.1g
In a butane lighter, 9.7 g of butane reacts with 34.7 g of oxygen to form 29.3 g of carbon dioxide. To determine the mass of water formed, we need to calculate the moles of carbon dioxide produced and then use the balanced chemical equation to determine the moles of water formed.
Explanation:In a butane lighter, 9.7 g of butane reacts with 34.7 g of oxygen to form 29.3 g of carbon dioxide.
To determine the mass of water formed, we need to calculate the moles of carbon dioxide produced and then use the balanced chemical equation to determine the moles of water formed.
From the balanced equation:
2 C4H10 + 13 O2 → 8 CO2 + 10 H2O
Based on the equation, for every mole of carbon dioxide formed, we have 10/8 moles of water. Therefore, the moles of carbon dioxide produced can be calculated as:
Moles of CO2 = (mass of CO2 / molar mass of CO2)
The mass of water formed can then be calculated as:
Mass of H2O = (moles of CO2) * (molar mass of H2O)
Learn more about Stoichiometry here:https://brainly.com/question/30218216
#SPJ3
Does this equation support the law of conservation of mass?
this equation does support the law of conservation of mass.
which statement is true of any chemical reaction?
A) the mass of the reactants is always greater than the mass of the products
B) The mass of the products is always greater than the mass of the reactants
C) there is no relationship between the mass of the reactants and products
D) the mass of the reactants equals the mass of the products
According to the Law of Conservation of Mass,
The mass of the products in a chemical reaction must equal the mass of the reactants.
∴ D is the Answer
Answer:
D) the mass of the reactants always equals the mass of the products
Explanation:
I got this right during a test :)
Can someone PLEASE HELP me?
How can you tell if a bond is Covalent?
which of these substance are likely to have a bitter taste antacod vi ger or anyacod toothpaste or orange jucoe and vinger or orange juice toothpaste
Answer : The correct option is, Antacid and toothpaste.
Explanation :
The property of an acid is that they are sour in taste and the property of base is that they are bitter in taste.
In the given question, vinegar, orange juice are the acids and antacids, toothpaste are the bases.
Therefore, the option Antacid and toothpaste are likely to have a bitter taste.
How do properties, such as Density, help us to classify and identify matter?
Density can be defined in terms of the mass of a substance present in a certain volume.
i.e. Density = Mass/ volume
It helps classify and identify matter due to the following reasons:
1) Density is an intensive property. For a given substance the density will remain the same irrespective of the amount in which it is present.
For example: The density of Aluminum (Al) = 2.7 g/cm3. This value is a constant at a certain temperature and pressure. Therefore, the density will remain the same for 1 kilogram or 1 mg of Al
2) Different elements/compounds have different values of densities which is characteristic of that substance
What is the chemical formula for aluminum fluoride? A) Al3F B) AlF C) AlF3 D) AlFl3
Answer : The chemical formula for aluminum fluoride is [tex]AlF_3[/tex]
Explanation :
Ionic compound : It is defined as the compound which is formed when electron gets transferred from one atom to another atom.
Ionic compound are usually formed when a metal reacts with a non-metal.
The nomenclature of ionic compounds is given by:
1. Positive ion is written first.
2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
3. In case of transition metals, the oxidation state are written in roman numerals in bracket in-front of positive ions.
The given compound is, aluminum fluoride.
Aluminum fluoride is an ionic compound because aluminum element is a metal and fluorine element is a non-metal. The bond formed between a metal and a non-metal is always ionic in nature.
The charge on aluminum is (+3) and the the charge on fluorine is (-1). Both combine with the an ionic bond by the criss-cross method. Thus, the formula of the compound potassium chloride will be [tex]AlF_3[/tex]
Hence, the chemical formula for aluminum fluoride is [tex]AlF_3[/tex]
The chemical formula for aluminium fluoride is AlF₃. Therefore, option C is correct.
A chemical formula is a notation that represents the composition of a chemical compound. It uses chemical symbols and subscripts to indicate the types and number of atoms present in the compound.
In the chemical formula, the chemical symbols of the elements are used to represent the different types of atoms. Subscripts are used to indicate the number of atoms of each element in the compound. They are written as small numbers to the right of the chemical symbol.
Learn more about chemical formula, here:
https://brainly.com/question/29031056
#SPJ6
What are some common properties of covalent compounds
Most covalent compounds have relatively low melting points and boiling points.
Covalent compounds usually have lower enthalpies of fusion and vaporization than ionic compounds.
Covalent compounds tend to be more flammable than ionic compounds.
Covalent compounds are characterized by their lower melting and boiling points, poor conductivity, varied solubility in water depending on molecular polarity, and being typically gases or liquids at room temperature. These properties stem from the sharing of electrons between nonmetallic elements, forming covalent bonds.
Covalent compounds exhibit unique characteristics due to the sharing of electrons between nonmetallic elements. These shared electrons create bonds that are central to the distinct properties of covalent compounds. A deeper understanding of these properties highlights the differences between covalent and ionic compounds.
Key Properties of Covalent Compounds
Lower Melting and Boiling Points: Covalent compounds generally have much lower melting and boiling points compared to ionic compounds. This is because the intermolecular forces in covalent compounds are weaker than the ionic bonds in ionic compounds.Poor Conductivity: In any state, whether solid, liquid, or gas, covalent compounds are poor conductors of electricity because they are electrically neutral.Solubility: Most covalent compounds are insoluble in water, and their solubility largely depends on molecular polarity.Physical State: Many covalent compounds are liquids or gases at room temperature, indicating their weaker forces and lower energy stability compared to ionic compounds, which are often solid.In essence, covalent bonding results in compounds with distinct physical states and functionalities, emphasizing the diversity of chemical compounds and their varied applications.
Is a microvilli is a tiny finger like projection that kills bacteria in the lymphatic system? true or false
Villi are tiny finger like projections present in the inner epithelial lining of the intestine. Each finger like villi is further divided into microvilli, which is the extension of plasma membrane of each epithelial cell of the villi. These villi and microvilli present on the inner surface of the intestine provide a greater surface area and this enhances the digestion and absorption of the nutrients.
Therefore, the correct answer is false as a microvilli is the tiny finger like projection of the inner epithelial cells of the small intestine that has absorptive functions.