Question

Question
1
Question
2
Question
3
A)
The atomic mass unit is equivalent to
of the mass of a neutral atom of which element?
(1 point)
1
12
carbon
oxygen
gold
hydrogen
A)
For an element, how does Avogadro’s number connect the atomic and macroscopic scales?
(1 point)
It describes the number of atoms in 1 gram of an element.
It describes the number of moles in 1 gram of an element.
It describes the number of atoms in 1 mole of an element.
It describes the number of grams in 1 mole of an element.
A)
The atomic mass of the element platinum (Pt) is 195.08 amu. How many atoms of platinum are in195.08 grams?
(1 point)
atoms
1.175
×
10
26
atoms
1.951
×
10
25
atoms
3.087
×
10
21
atoms
6.022
×
10
23
Question
4
Question
5
A)
The atomic mass of the element niobium (Nb) is 92.906 amu. Which measurement is correct?
(1 point)
1 gram of Nb = 92.906 atoms
1 mole of Nb = 92.906 grams
1 mole of Nb = 92.906 atoms
1 gram of Nb = 92.906 moles
A)
The atomic mass of copper (Cu) is 63.546 amu, the atomic mass of sulfur (S) is 32.065, and theatomic mass of oxygen (O) is 15.999 amu. Which molar mass is correct for copper sulfate (CuSO
)?
(1 point)
4
225.802 g/mol
446.440 g/mol
111.610 g/mol
159.607 g/mol

Answer 1

1) Carbon (the amu is 1/12 the mass of a neutral 12C atom).

2) It describes the number of atoms in 1 mole of an element.

3) 6.022 × 10^23 atoms (195.08 g Pt = 1.00 mol Pt).

4) 1 mole of Nb = 92.906 grams.

5) 159.607 g/mol (63.546 + 32.065 + 4×15.999 = 159.607).