To express 87,449 in scientific notation with four significant figures, it's written as 8.745 × 104. The number 0.000066600 in scientific notation with five significant figures is expressed as 6.6600 × 10-5.
Explanation:To express the number 87,449 in scientific notation with four significant figures, you need to place the decimal after the first digit and count the number of places you move it. In this case, the decimal is moved 4 places to the left: 8.7449 becomes 8.744. Now, we need just four significant figures, so it rounds to 8.745. This gives us 8.745 × 10 to the power of 4, or 8.745 × 104.
Writing the number 0.000066600 in scientific notation with five significant figures involves moving the decimal point 5 places to the right, giving us 6.6600 which rounds to 6.6600 with five significant figures. This becomes 6.6600 × 10 to the negative fifth power, or 6.6600 × 10-5.
How many molecules of hypothetical substance b are produced when 29.9g of hypothetical substance a reacts? the molar mass of substance a is 15.7 g/mol?
1. **Convert the mass of A to moles:**
- [tex]\(29.5 \, \text{g}\)[/tex] of A is approximately [tex]\(1.88 \, \text{mol}\)[/tex].
2. **Convert the number of moles of A to the number of moles of B:**
- [tex]\(1.88 \, \text{mol}\)[/tex] of A corresponds to approximately [tex]\(2.82 \, \text{mol}\)[/tex] of B.
3. **Convert the number of moles of B to the molecules of B:**
- [tex]\(2.82 \, \text{mol}\)[/tex] of B is approximately [tex]\(1.70 \times 10^{24}\)[/tex] molecules.
**Convert the mass of A to moles:**
The first step is to convert the mass of substance A to moles using its molar mass. The formula for moles [tex](\(n\))[/tex] is given by the mass [tex](\(m\))[/tex] divided by the molar mass [tex](\(M\)):[/tex]
[tex]\[ n_A = \frac{m_A}{M_A} \][/tex]
Given that the mass of substance A [tex](\(m_A\))[/tex] is 29.5 g and its molar mass [tex](\(M_A\))[/tex] is 15.7 g/mol:
[tex]\[ n_A = \frac{29.5 \, \text{g}}{15.7 \, \text{g/mol}} \approx 1.88 \, \text{mol} \][/tex]
**Convert the number of moles of A to the number of moles of B:**
The reaction ratio states that 2 moles of A produce 3 moles of B. Therefore, if [tex]\(n_A\)[/tex] is 1.88 mol, the corresponding moles of B [tex](\(n_B\))[/tex] can be calculated using the ratio:
[tex]\[ n_B = \frac{3}{2} \times n_A \][/tex]
[tex]\[ n_B = \frac{3}{2} \times 1.88 \, \text{mol} \approx 2.82 \, \text{mol} \][/tex]
**Convert the number of moles of B to the molecules of B:**
To convert moles of B to molecules [tex](\(N_B\))[/tex], you use Avogadro's number [tex](\(6.022 \times 10^{23}\) mol\(^{-1}\)):[/tex]
[tex]\[ N_B = n_B \times N_A \][/tex]
[tex]\[ N_B = 2.82 \, \text{mol} \times (6.022 \times 10^{23} \, \text{mol}^{-1}) \approx 1.70 \times 10^{24} \, \text{molecules} \][/tex]
The question probable may be:
In a chemical reaction, exactly 2 mol of substance A react to produce exactly 3 mol of substance B.
How many molecules of substance B are produced when 29.5 g of substance A reacts? The molar mass of substance A is 15.7 g/mol.
Convert the mass of A to moles
Convert the number of moles of A to the number of moles of B
Convert the number of moles of B to the molecules of B
how much would the boiling point of water increase if 4 mol of suagr were added to 1kg of water
need help asap
What is the velocity of an car that travels 50 miles north, turns around and travels 50 miles south, in 5 hours?
Question 6 options:
5 mph south
2 mph south
0
25 mph north
Synfuels are made from energy sources that are more plentiful than _____.
carbon
oil
sunlight
water
The answer is: oil.
Synfuel (synthetic fuel) is a liquid fuel, rarely gaseous fuel, made from syngas.
Syngas is a mixture of carbon monoxide (CO) and hydrogen (H₂).
Syngas goes to additional conversion process to become liquid fuel.
Some methods for manufacturing synthetic fuels are methanol (CH₃OH) to gasoline conversion and direct coal liquefaction.
Express a time period of exactly 7 day in terms of seconds.
Which statement is true when a crystal is formed from many metal atoms? .A. There are no bands being formed.. B.There are many molecular orbitals.. C.There are only unshared atomic orbitals.. D.There are many electrons lost to other atoms.
Crystal formation form many metals results into combining of many molecular orbitals during formation.
This is because each metallic atomic orbital contributes for the formation of crystal.
When compared with the relative energies of the molecular orbitals it was found that they have lower energy than the atomic orbitals. Thus the new crystals are stable in nature.
If the mass of an object increases, the force acting on it, such as gravitational force, also increases.
Answer:
Gravitational force will increase with greater mass
Calculate the mass of naoh needed to prepare 100. ml of 0.15m solution.
To prepare 100 mL of a 0.15 M NaOH solution, you will need approximately 0.60 g of NaOH.
Explanation:To calculate the mass of NaOH needed to prepare a 0.15 M solution, we need to use the formula:
Mass (g) = Molarity (M) x Volume (L) x Molar Mass (g/mol)
In this case, the molarity is 0.15 M and the volume is 100 mL (or 0.1 L). The molar mass of NaOH is 22.990 + 15.999 + 1.008 = 39.997 g/mol.
Mass (g) = 0.15 M x 0.1 L x 39.997 g/mol = 0.5999 g, which can be rounded to 0.60 g.
The isotope 3115p is also called ___________
phosphorus-46
phosphorus-31
phosphorus-16
phosphorus-15
What is the process where a liquid changes from its liquid state to a gaseous state?
Answer:
evaporation
Explanation:
Evaporation is the process where a liquid, in this case water, changes from its liquid state to a gaseous state. Liquid water becomes water vapor. Although lower air pressure helps promote evaporation, temperature is the primary factor.
How many moles are in 1.2 x10^3 grams of ammonia, NH3
You have a 70% solution of dextrose. how many grams of dextrose are in 500 ml of this solution?
Answer:
350g dextrose
Explanation:
To calculate how many g of dextrose are in 500ml of solution we have to know the following:
When we talk about x% m/v (mass / volume) it means that there are x grams of solute in 100 ml of solution. Then 70% means that there is 70g of dextrose per 100ml of solution.
To solve this we can say that if in 100 ml there are 70g. How many grams are in 500 ml?
We apply the simple three rule and solve:
100ml -----------> 70g dextrose
500ml----------> X g dextrose
500ml x 70g / 100ml = X
350g = X
There are 350 grams of dextrose in 500 ml of the 70% dextrose solution.
A 70% solution of dextrose means that the solution contains 70 grams of dextrose per 100 milliliters of solution.
To calculate the grams of dextrose in 500 ml of this solution, we can set up a proportion:
(70 g / 100 ml) = (x g / 500 ml)
To solve for x, we can cross-multiply and then divide:
70 g * 500 ml = 100 ml * x g
35,000 g·ml = 100 ml * x g
Dividing both sides by 100 ml: 350 g = x g
Thus, there are 350 grams of dextrose in 500 ml of the 70% dextrose solution.
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What volume will a balloon occupy at 1.0 atm, if the balloon has a volume of 4.4 l at 2.2 atm?
The volume of balloon at 1.0 atmis [tex]\boxed{9.68{\text{ L}}}[/tex].
Further Explanation:
A hypothetical gas comprising of a large number of randomly moving particles is called ideal gas. The collisions between such particles are considered to be perfectly elastic. Practically, no gas can be ideal so it is just a theoretical concept.
Given information:
Volume of balloon at 2.2 atm: 4.4 L
To determine:
Volume of balloon at 1.0 atm
Boyle’s law:
This law describes relationship between volume and pressure of gas. According to this law,volume of the gas is inversely proportional to its pressure, provided the temperature and the number of moles of gas remain constant. Mathematical form of Boyle’s law is,
[tex]{\text{P}} \propto \dfrac{1}{{\text{V}}}[/tex]
Or,
[tex]{\text{PV}} = {\text{k}}[/tex]
Where,
V is volume occupied by the gas.
P is the pressure of the gas.
k is a constant.
At two volumes [tex]{{\text{V}}_{\text{1}}}[/tex] and [tex]{{\text{V}}_{\text{2}}}[/tex] andpressures [tex]{{\text{P}}_{\text{1}}}[/tex] and [tex]{{\text{P}}_{\text{2}}}[/tex], equation of Boyle’s law modifies as follows:
[tex]{{\text{P}}_1}{{\text{V}}_1} = {{\text{P}}_2}{{\text{V}}_2}[/tex] …… (1)
Rearrange equation (1) to calculate [tex]{{\text{V}}_{\text{2}}}[/tex].
[tex]{{\text{V}}_2} = \dfrac{{{{\text{P}}_1}{{\text{V}}_1}}}{{{{\text{P}}_2}}}[/tex] …… (2)
Substitute 4.4 L for [tex]{{\text{V}}_{\text{1}}}[/tex] , 2.2 atm for [tex]{{\text{P}}_{\text{1}}}[/tex] and 1.0 atm for [tex]{{\text{P}}_{\text{2}}}[/tex] in equation (2).
[tex]\begin{aligned}{{\text{V}}_2} &= \frac{{\left( {2.2{\text{ atm}}} \right)\left( {4.4{\text{ L}}} \right)}}{{\left( {{\text{1}}{\text{.0 atm}}} \right)}} \\&= 9.68{\text{ L}} \\\end{aligned}[/tex]
Learn more:
Which statement is true for Boyle’s law: https://brainly.com/question/1158880 Calculation of volume of gas: https://brainly.com/question/3636135Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Ideal gas equation
Keywords: Boyle’s law, P, V, k, pressure of gas, volume occupied by gas, constant, temperature, ideal gas, 2.2 atm, 1.0 atm, 4.4 L, 9.68 L.
What subatomic particle is specifically responsible for combining the atoms together to form a new substance?
The electron is the subatomic particle that is specifically responsible for combining atoms together to form a new substance. It does this through chemical bonding, where the outer shell electrons of atoms interact with each other. This process forms the basis of all matter in the universe.
Explanation:In the formation of substances, the subatomic particle that is specifically responsible for combining atoms together is the electron. In chemical bonds, it's the exterior electrons of the atoms that interact and form these bonds. For instance, in the formation of a molecule of water (H₂O), two hydrogen atoms and one oxygen atom bond together, facilitated by the interactions of their electrons.
Atoms are the fundamental building blocks of matter, made up of different subatomic particles, namely electrons, protons, and neutrons. The atom is regarded as the smallest unit of an element that carries the properties of that element. However, it's the electrons in the outer shell of an atom that play an integral role in the formation of different substances via chemical bonding.
These chemical bonds are the basis for all matter in the universe, ranging from the ionic lattice structure of NaCl (common salt) to covalent molecular structures like proteins and sugars found in living organisms. Therefore, comprehending the role of electrons in the atomic construction of matter is key to understanding the vast array of chemical phenomena that occur in our universe.
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Name the product formed by the reduction of d-gulose.
Final answer:
Reduction of D-gulose typically produces D-gulitol (sorbose alcohol), a sugar alcohol. This reaction is analogous to the reduction of D-glucose to sorbitol, involving conversion of the aldehyde group to an alcohol.
Explanation:
The student asked about the product formed by the reduction of D-gulose. D-Gulose, an aldose sugar, can undergo reduction to yield a sugar alcohol, similar to how D-glucose can be reduced to sorbitol. In the case of D-gulose, the reduction typically would produce D-gulitol, also known as sorbose alcohol.
The reducing sugar characteristic mentioned in reference to lactose is due to the presence of a free aldehyde group or an equivalent group in cyclic forms that can act as a reducing agent, for instance in Fehling's solution or Tollen's reagent reactions. This is relevant because the reduction of D-gulose would involve the conversion of its aldehyde group to an alcohol.
Name the two properties of elections that indicate a wave-like nature.
What is the energy associated with an object’s motion called
How do you know a chemical reaction has occurred in a candle?
Evaporation is ________. check all that apply. check all that apply. an endothermic process sometimes a warming process always a cooling process sometimes a cooling process an exothermic process always a warming process
Evaporation is an endothermic process that requires the absorption of heat to occur, typically resulting in a perceived cooling effect. However, it is not inherently a cooling or warming process, nor is it an exothermic process.
Explanation:Evaporation is an endothermic process, meaning it requires an input of heat to occur. The heat energy is used to overcome intermolecular attractions, allowing matter to change from one physical state to another. This is why when you leave a swimming pool or when you sweat, you feel cool. The process of evaporation absorbs heat from your body.
However, it's important to note that evaporation is not always a cooling process. While evaporation takes heat from the source, it doesn't inherently reduce the temperature of the source, the perceived cooling is due to the loss of heat. Also, evaporation is not a warming process, or an exothermic process, as it doesn't produce heat. In fact, the reverse process of evaporation - condensation - is exothermic, releasing heat as matter changes state.
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For a half-reaction in an acidic solution, which substances should you add to balance the equation?
H+ and H2O
H+ and OH−
H2O and NO2
OH−
Secondary colors can be created from a mixture of __________
Secondary colors can be created from a mixture of primary colors, namely red, blue, and yellow. This is part of the subtractive color process. In the additive color process that involves light, the primary colors are red, green, and blue.
Explanation:Secondary colors can be created from a mixture of primary colors, which are red, blue, and yellow. When these primary colors are mixed in the right proportions, they can produce secondary colors. For example, mixing red and blue in equal proportions results in purple, a secondary color. Similarly, a mixture of blue and yellow generates green, while red and yellow produce orange. These are examples of the subtractive color process, often associated with pigment mixing.
The human eye perceives a mixture of all colors in sunlight as white light. This fact is related to the additive color process, primarily concerned with light. Specifically, in this process, red, green, and blue are treated as primary colors. Their combinations can yield secondary colors, and when combined at full intensity, they give white light.
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The enthalpy of formation of liquid ethanol (c2h5oh) is −277.6 kj/mol. what is the equation that represents the formation of liquid ethanol?
The enthalpy of formation of liquid ethanol (C2H5OH) is represented by the chemical equation combining carbon (solid), hydrogen gas, and oxygen gas to form ethanol.
The enthalpy of formation of liquid ethanol (C2H5OH) can be represented by the balanced chemical equation showing its formation from its elements in their standard states.
The equation is as follows:
C(s) + 3H2(g) + 1/2O2(g) → C2H5OH(l)
The enthalpy change for this reaction is -277.6 kJ/mol, indicating that the formation of liquid ethanol from its elements is exothermic.
Zn(s)+cu2+(aq)→zn2+(aq)+cu(s). part a under standard conditions, what is the maximum electrical work, in joules, that the cell can accomplish if 51.0 g of copper is plated out?
the maximum electrical work that the cell can accomplish when 51.0 g of copper is plated out is approximately [tex]\( -167549 \, \text{J} \).[/tex]
To find the maximum electrical work that the cell can accomplish when 51.0 g of copper is plated out, we can use the relationship between electrical work ( w ) and the amount of substance involved in the redox reaction.
The electrical work ( w ) done by a cell operating under standard conditions is given by:
[tex]\[ w = -nFE \][/tex]
Where:
- ( n ) is the number of moles of electrons transferred in the balanced redox reaction.
- ( F ) is the Faraday constant [tex](\( 96485 \, \text{C/mol} \)).[/tex]
- ( E ) is the standard cell potential of the redox reaction (in volts).
First, we need to determine the number of moles of electrons transferred in the reaction. From the balanced redox reaction:
[tex]\[ \text{Zn}(s) + \text{Cu}^{2+}(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{Cu}(s) \][/tex]
We see that 2 moles of electrons are transferred for every 1 mole of copper plated out.
Given that the molar mass of copper ([tex]\( \text{Cu} \))[/tex] is approximately [tex]\( 63.55 \, \text{g/mol} \)[/tex], we can calculate the number of moles of copper plated out:
[tex]\[ \text{Moles of Cu} = \frac{\text{Mass}}{\text{Molar mass}} = \frac{51.0 \, \text{g}}{63.55 \, \text{g/mol}} \][/tex]
[tex]\[ \text{Moles of Cu} \approx 0.802 \, \text{mol} \][/tex]
Since 2 moles of electrons are transferred for every 1 mole of copper plated out, the number of moles of electrons transferred (\( n \)) is twice the number of moles of copper plated out:
[tex]\[ n = 2 \times 0.802 \, \text{mol} \][/tex]
[tex]\[ n = 1.604 \, \text{mol} \][/tex]
Now, we can use the standard reduction potentials to find the standard cell potential (E ) for the reaction. From the standard reduction potentials table, we have:
[tex]\[ E^\circ_{\text{cell}} = E^\circ_{\text{cathode}} - E^\circ_{\text{anode}} \][/tex]
[tex]\[ E^\circ_{\text{cell}} = E^\circ_{\text{Cu}^{2+}/\text{Cu}} - E^\circ_{\text{Zn}^{2+}/\text{Zn}} \][/tex]
Given that [tex]\( E^\circ_{\text{Cu}^{2+}/\text{Cu}} = 0.34 \, \text{V} \) and \( E^\circ_{\text{Zn}^{2+}/\text{Zn}} = -0.76 \, \text{V} \)[/tex], we have:
[tex]\[ E^\circ_{\text{cell}} = (0.34 \, \text{V}) - (-0.76 \, \text{V}) \][/tex]
[tex]\[ E^\circ_{\text{cell}} = 1.10 \, \text{V} \][/tex]
Now, we can calculate the maximum electrical work [tex](\( w \)):[/tex]
[tex]\[ w = -nFE \][/tex]
[tex]\[ w = -(1.604 \, \text{mol} \times 96485 \, \text{C/mol} \times 1.10 \, \text{V}) \][/tex]
[tex]\[ w \approx -1.604 \times 96485 \times 1.10 \, \text{J} \][/tex]
[tex]\[ w \approx -167548.6 \, \text{J} \][/tex]
[tex]\[ w \approx -167549 \, \text{J} \][/tex]
So, the maximum electrical work that the cell can accomplish when 51.0 g of copper is plated out is approximately [tex]\( -167549 \, \text{J} \).[/tex]
Suppose you find a rock originally made of potassium-40, half of which decays into argon-40 every 1.25 billion years. You open the rock and find 31 atoms of argon-40 for every atom of potassium-40. How long ago did the rock form?
We see that in 1 rock, there are 31 atoms of Argon and 1 atom of Potassium so the relative concentration of Potassium is:
1 / 32
or can be written as:
1 / 2^5
So this means that 5 half-lives have passed.
So the years are:
years passed = 5 * 1.25 billion years = 6.25 billion years
Answer:
1.3 billion years
Explanation:
Calcium has an atomic mass of 40 and an atomic number of 20, so the number of neutrons must be _______________
The atom would have 20 neutrons.
Mass number = neutrons + protons
40 = neutrons + 20
neutrons = 40 – 20 = 20
How many moles of al(cn)3 are in 225 g of the compound?
Why does carbon acculate quicker in boreal peatlands?
The boiling temperature of water is so much higher than that of methane because water molecules are
The element in the top left corner of the periodic table is ______________.answer:
chemistry omg need help plz I need plz. I real badly at it and try to get better but plz help me