1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Zolol [24]
3 years ago
12

A sample of gold (Au) has a mass of 45.39 g.

Chemistry
1 answer:
professor190 [17]3 years ago
8 0
<span>1. What is the molar mass of gold?
Molar mass is a unit that expresses the mass of a molecule per one mol. The molar mass can be obtained by adding the neutron with the proton of the atoms. Gold has atomic number 79 so the proton is 79. The number of the neutron is 118. Then the molar mass would be: 79 + 118 = </span>197 g/mol<span>


</span><span>2. Calculate the number of moles of gold (Au) in the sample. Show your work. 
</span>In this question, you are given the mass of the gold and asked for how many moles the sample has. To find the number of moles you just need to divide the weight by the molar mass.
For 45.39 grams of gold, the number of moles would be:
45.39 / (197g/mol)= 0.23 moles


3. Calculate the number of atoms of gold (Au) in the sample. Show your work.Moles is unit of a number of molecules but 1 mol doesn't represent 1 molecule. The number of atoms can be obtained by multiplying the number of moles with Avogadro number. The calculation would be:
0.23 moles * (6.023 * 10^23 molecules/mol)= 1.387 * 10^23 molecules
You might be interested in
Which lists the waves in order of frequency, from highest to lowest?
serg [7]
Radio waves.
microwaves.
infrared waves.
light.
ultraviolet waves (rays)
x-rays.
gamma rays.
6 0
3 years ago
Read 2 more answers
Find the mass of 3.02 mol Cl2.<br> Answer in units of g.
Evgen [1.6K]

Answer:

the answer is 70.906 g/mol

Explanation:

7 0
3 years ago
Read 2 more answers
harry potter flips a coin (not magical ) 8 times. He gets heads 1 time. What are the odds that his next flip will be heads? A 10
rodikova [14]
C. 50%
Unless the question is saying he only gets heads once, in which case it would be 0%. Or the coin could have 2 heads. Then it would be 100%.
But I'm pretty sure it's 50%.
7 0
3 years ago
The theoretical yield of Cl2 from certain starting amounts of MnO2 and HCl was calculated as 60.25 g and 65.02 g, respectively.
hoa [83]

The actual yield is 43 g Cl₂.

The <em>limiting reactant was MnO₂</em> because it gave the smaller mass of Cl₂.

∴ The <em>theoretical yield</em> is 60.25 g Cl₂.

% yield = actual yield/theoretical yield × 100 %

Actual yield = theoretical yield × (% yield/100 %) = 60.25 g × (72 %/100%) = 43 g

8 0
3 years ago
For the following reaction, 6.94 grams of water are mixed with excess sulfur dioxide . Assume that the percent yield of sulfurou
Alexxx [7]
<h3>Answer:</h3>

#a. Theoretical yield = 31.6 g

#b. Actual yield = 25.72 g

<h3>Explanation:</h3>

The equation for the reaction between sulfur dioxide and water to form sulfurous acid is given by the equation;

SO₂(g) + H₂O(l) → H₂SO₃(aq)

The percent yield of H₂SO₃ is 81.4%

Mass of water that reacted is 6.94 g

#a. To get the theoretical yield of H₂SO₃ we need to follow the following steps

Step 1: Calculate the moles of water

Molar mass of water = 18.02 g/mol

Mass of water = 6.94 g

But, moles = Mass/molar mass

Moles of water = 6.94 g ÷ 18.02 g/mol

                        = 0.385 mol

Step 2: Calculate moles of H₂SO₃

From the equation, the mole ratio of water to H₂SO₃ is 1 : 1

Therefore, moles of water = moles of H₂SO₃

Hence, moles of H₂SO₃ = 0.385 mol

Step 3: Theoretical mass of H₂SO₃

Mass = moles × Molar mass

Molar mass of H₂SO₃ = 82.08 g/mol

Number of moles of H₂SO₃ = 0.385 mol

Therefore;

Theoretical mass of H₂SO₃ = 0.385 mol ×  82.08 g/mol

                                             = 31.60 g

Thus, the theoretical yield of H₂SO₃ is 31.6 g

<h3>#b. Calculating the actual yield</h3>

We need to calculate the actual yield

Percent yield of H₂SO₃ is 81.4%

Theoretical yield is 31.60 g

But; Percent yield = (Actual yield/theoretical yield)×100

Therefore;

Actual yield = Percent yield × theoretical yield)÷ 100

                   = (81.4 % × 31.6) ÷ 100

                  = 25.72 g

The percent yield of H₂SO₃ is 25.72 g

6 0
3 years ago
Other questions:
  • Why are alphabets in the order they are?
    11·1 answer
  • Genes help determine a person's traits or characteristics. scientific investigations into genes have helped scientists solve maj
    15·2 answers
  • You find two containers on a chemical shelf, one labeled Cu2O(s) and a second labeled CuO(s). Are these substances the same or d
    13·1 answer
  • A turbine operates on superheated steam that enters at 80 bar absolute and 500˚C, and leaves the turbine at 7.5 bar absolute and
    14·1 answer
  • _______ is the type of heat that cooks the fruit.
    15·1 answer
  • How do you find empirical formula
    8·1 answer
  • 1) Calculate the molarity of a solution produced by dissolving 35.7 g of solid Cu(ClO3)2 in enough water to make 250 mL of solut
    8·1 answer
  • Study the image. Earth showing air mass movement. Purple and red arrows are moving in a counterclockwise direction. Based on the
    13·2 answers
  • Hermit crabs and anemones have a mutualistic relationship. Which of these statements best describes how they interact?
    7·1 answer
  • PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE H
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!