Homework #28: 4/18 Quiz Review

Which two terms represent types of chemical formulas? (Choose two)

• mechanical

• structural

• empirical

• nonpolar

• polar

As plants grow, light energy is converted into chemical energy during the process of photosynthesis. The reaction produces glucose and oxygen. The balanced equation below represents photosynthesis.

6CO₂ + 6H₂O + light energy --> C₆H₁₂O₆ + 6O₂

Write the empirical formula for glucose

• CH₂O

• CH₃O

• C₃H₆O₃

• C₆H₁₂O₆

Given the incomplete equation representing a reaction:

2C₆H₁₄+ ___O₂ --> 12CO₂ + 14H₂O

• 19

• 13

• 14

• 26

What is the mole ratio of H₂O to H₃PO₄ in the following chemical equation?   P₄O₁₀ + 6 H₂O --> 4 H₃PO₄ 

• 6:4
• 4:6
• 1:3
• 3:1

Tags

NGSS.HS-PS1-7

2C + O₂ -->2CO
If 12g of Carbon react with 16g of Oxygen, what is the total mass of carbon monoxide (CO) is formed? 

• 28 g
• 4g
• 30g
• 12g
• 56g

Tags

NGSS.HS-PS1-7

2NO(g) + O₂(g) --> 2NO₂(g) + heat

Show a numerical setup for calculating the gram-formula mass of the NO₂(g) produced in equation

There will be an audio explanation on next slide

• 14.0067 g/mol
  +
  2(15.9994) g/mol

• 14.0067 g/mol
  +
  15.9994)g/mol

• 2(14.0067) g/mol
  +
  (15.9994) g/mol

• 2(14.0067) g/mol
  +
  2(15.9994) g/mol

Answer explanation

2NO(g) + O₂(g) --> 2NO₂(g) + heat

Show a numerical setup for calculating the gram-formula mass of the NO₂(g) produced in equation

1(14.0067) g/mol
+
2(15.9994) g/mol

Tags

NGSS.HS-PS1-7

Which term represents the sum of the atomic masses of the atoms in a molecule? (Choose two)

• atomic number

• mass number

• formula mass

• percent composition by mass

• gram formula mass

What is correct numerical setup for the percent composition by mass of nitrogen in (NH₄)₂CO₃ (Choose two)
(gram-formula mass = 96.0 g/mol)?

Nitrogen has an average atomic mass of 14g

• 14g/96.0g

• 28g/96.0g

• (2)(14g)/96.0g

• (1)(14g)/96.0g

What is the correct numerical setup for the percent composition by mass of sulfur in the compound MgSO₄
(gram-formula mass = 120. grams per mole)?

Sulfur has an average mass of 32

• 16g/120.g x 100

• 32g/120.g x 100

• (4)(32g)/120.g x 100

• (4)(16g)/120.g. x 100

A student determines the density of a copper sample at room temperature to be 9.46 g/cm³ . Based on Table S, what is the student's percent error in determining the density of copper? (Choose two)

Hint: Use the image for Table S

• Wrong - Correct x 100
  Correct

• 9.46g - 8.96g x 100
  8.96g

• 8.96g - 9.46g x 100

  9.46g

• Correct - Wrong x 100
  Wrong