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3 years ago

What is the correct value using 2 significant figures for 14.8232 g/mol?

Chemistry

1 answer:

alexgriva [62]3 years ago

8 0

Answer:

15 g/mol

Explanation:

If you need to round 14.8232 g/mol down to 2 significant figures, you start on the left, count in two (14) and round with the next number (.8).

Because 8 is higher than 4, you round up, getting the answer 15.

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Calculating the expected pH of the buffer solution: Given that the pKa for Acetic Acid is 4.77, calculate the expected pH of the

ser-zykov [4K]

Answer:

$pH=4.77$

Explanation:

From the question we are told that:

pKa for Acetic Acid $pK_a= 4.77$

Therefore

For Equal Concentration of acetic acid and acetatic ion

$CH_3COOH=CH_3COO^-$

Generally the Henderson's equation for pH value is mathematically given by

$pH=pK_a+log\frac{base}{acid}$

$pH=4.77+log\frac{CH_3COO^-}{CH_3COOH}$

$pH=4.77+log1$

$pH=4.77$

5 0

3 years ago

If 5.85 moles of CaCO3 are used in an experiment, how many moles of carbon dioxide are created? (Be sure to include units in you

azamat

Answer:

5.85 moles of carbon dioxide are created.

Explanation:

The balanced reaction is:

CaCO₃ → CaO + CO₂

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

CaCO₃: 1 mole
CaO: 1 mole
CO₂: 1 mole

Then you can apply the following rule of three: if by stoichiometry 1 mole of CaCO₃ produces 1 mole of CO₂, 5.85 moles of CaCO₃ will produce how many moles of CO₂?

$moles of CO_{2}=\frac{5.85 moles of CaCO_{3} *1mole of CO_{2} }{1 mole of CaCO_{3}}$

moles of CO₂= 5.85

5.85 moles of carbon dioxide are created.

7 0

3 years ago

A chemist fills a reaction vessel with mercurous chloride solid, mercury (I) aqueous solution, and chloride aqueous solution at

makvit [3.9K]

Answer:

ΔG° = -533.64 kJ

Explanation:

Let's consider the following reaction.

Hg₂Cl₂(s) ⇄ Hg₂²⁺(aq) + 2 Cl⁻(aq)

The standard Gibbs free energy (ΔG°) can be calculated using the following expression:

ΔG° = ∑np × ΔG°f(products) - ∑nr × ΔG°f(reactants)

where,

ni are the moles of reactants and products

ΔG°f(i) are the standard Gibbs free energies of formation of reactants and products

ΔG° = 1 mol × ΔG°f(Hg₂²⁺) + 2 mol × ΔG°f(Cl⁻) - 1 mol × ΔG°f(Hg₂Cl₂)

ΔG° = 1 mol × 148.85 kJ/mol + 2 mol × (-182.43 kJ/mol) - 1 mol × (-317.63 kJ/mol)

ΔG° = -533.64 kJ

3 0

3 years ago

Silver jewelry is a mixture of silver and copper. If a bracelet has a mass of 23.56 g, and it is 80.1% silver, the mass of silve

Reptile [31]

Answer:

18.87 g

Explanation:

80.1% of 23.56 g = 18.87 g is the mass of the silver

6 0

3 years ago

Problem PageQuestion The airbags that protect people in car crashes are inflated by the extremely rapid decomposition of sodium

Shalnov [3]

Answer:

1. 2NaN₃(s) → 2Na(s) + 3N₂(g)

2. 14.5 g NaN₃

Explanation:

The answer is incomplete, as it is missing the required values to solve the problem. An internet search shows me these values for this question. Keep in mind that if your values are different your result will be different as well, but the solving methodology won't change.

" The airbags that protect people in car crashes are inflated by the extremely rapid decomposition of sodium azide, which produces large volumes of nitrogen gas. 1. Write a balanced chemical equation, including physical state symbols, for the decomposition of solid sodium azide (NaN₃) into solid sodium and gaseous dinitrogen. 2. Suppose 71.0 L of dinitrogen gas are produced by this reaction, at a temperature of 16.0 °C and pressure of exactly 1 atm. Calculate the mass of sodium azide that must have reacted. Round your answer to 3 significant digits. "

1. The reaction that takes place is:

2NaN₃(s) → 2Na(s) + 3N₂(g)

2. We use PV=nRT to calculate the moles of N₂ that were produced.

P = 1 atm

V = 71.0 L

n = ?

T = 16.0 °C ⇒ 16.0 + 273.16 = 289.16 K

1 atm * 71.0 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 289.16 K

n = 0.334 mol

Now we convert N₂ moles to NaN₃ moles:

0.334 mol N₂ * $\frac{2molNaN_{3}}{3molN_2}$ = 0.223 mol NaN₃

Finally we convert NaN₃ moles to grams, using its molar mass:

0.223 mol NaN₃ * 65 g/mol = 14.5 g NaN₃

6 0

4 years ago