The Mole and Atomic Mass | Chemistry | Quiz

One "mole" in chemistry represents the number:

2.06 x 10²³

6.02 x 10²³

0.62 x 10²³

10.23 x 6²
The International Committee for Weights and Measures (ICWM) defines one mole as the number of atoms in exactly:

12 grams of any metal

1 gram of any metal

1 gram of carbon-12 (¹²C)

12 grams of carbon-12 (¹²C)
Since ¹²C’s molar mass is 12 grams, 48 grams of ¹²C atoms would be equal to ____ moles.

2

4

6

The answer cannot be determined
Avogadro’s number acts as the conversion factor for converting between the number of moles in a sample and the number of molecules in the sample.

true

false
If there are 0.20 moles in 8.9 grams of CO₂, what is the number of CO₂ molecules? Use this equation to find the answer: Moles in sample (mol) x Avogadro's number (6.022 x 10²³) = Number of sample molecules

0.20 x 10²³

1.2 x 10²³

8.9 x 10²³

20 x 10²³
Molar mass is a numerical value that represents ______.

the mass of a substance divided by the amount of that substance

the mass of a substance

the amount of a substance

the number of atoms in a molecule
An element’s molar mass and atomic weight are always equal.

false

true
The element Vanadium has two stable isotopes ⁵⁰V and ⁵¹V. The mass and abundance of these isotopes are ⁵⁰V = 49.9472 amu and .0025 abundance and ⁵¹V = 50.9440 amu and .9975 abundance. With this information, what is the atomic weight of Vanadium?

23

49.947

50.944

50.9415
The atomic weight of Hydrogen is 1.0079 amu and the atomic weight of Oxygen is 15.999 amu. Using this information, what is the molecular weight of a molecule of water, H₂O?

2.016 amu

17.007 amu

18.015 amu

Unknown
The definition of a mole is not open to scientific debate because it is unchanging.

false

true