Lesson 70: Mini Quiz

A 20g sample of an unknown compound contains 15 grams of carbon. What is the percent (by mass) of carbon in the compound?

• 15%

• 35%

• 50%

• 75%

What is the mass of 5 water molecules?

• 45 amu

• 85 amu

• 90 amu

• 100 amu

What is the mass of 37 glucose (C6H12O6) molecules?

• 2222 amu

• 6666 amu

• 7777 amu

• 9999 amu

Oxygen (O) is approximately what percent (by mass) of water (H20)?

• 5%

• 11%

• 59%

• 89%

46.0g of sodium reacts completely with 70.9g of chlorine. What is the percentage (by mass) of chlorine in the compound that is formed?

• 39.3%

• 60.7%

• 70.9%

• 116.9%

Using a periodic table, determine how much of a 200g sample of nitrous oxide (N2O) is nitrogen (N).

• 65g

• 127g

• 172g

• 256g

Using a periodic table, determine how much nitrogen (N)is in a 500g sample of ammonia (NH3)?

• 111

• 211g

• 311g

• 411g

• 511g

4 unknown compounds are tested and their components are shown. Which two are the same compounds?

• A and B

• B and C

• A and C

• B and D