Question

Determine if the statement is True or False.
The molar mass of ammonium acetate is 77.083 g/mol. A student uses 0.100 mol of ammonium acetatein a chemical reaction. The student claims that the reaction uses
of ammonium acetate, which has
molecules. Did the student determine the correct number ofmolecules of ammonium acetate used in the reaction?
(2 points)
(0.100 mol) (77.083 ) = 7.71 g g
mol
(7.71) (6.022 × 1023) = 4.64 × 1024
The student calculated the correct number of molecules of ammonium acetate.
The student miscalculated the number of molecules of ammonium acetate

Use this reaction to answer the question.
CH
CH
OH + 3 O
→ 2 CO
+ 3 H2O
Use the table of molar masses to complete the activity.
Element
Molar Mass (g/mol)
carbon
12.01
hydrogen
1.01
oxygen
16.00
A chemist will use a sample of 30 g of ethanol (CH
CH
OH) in an experiment. In 1-2 sentences, makeand justify a claim about the number of moles of ethanol the chemist will use by calculating the molarmass of ethanol and using it to find moles

Answer 1

First part — False. The student miscalculated. 0.100 mol × 77.083 g/mol = 7.71 g is correct, but molecules = moles × NA, so molecules = 0.100 mol × 6.022×10^23 mol^−1 = 6.02×10^22 molecules. Multiplying grams by Avogadro’s number (7.71 × 6.022×10^23 = 4.64×10^24) is incorrect.

Second part — Claim and justification (1–2 sentences):
Ethanol (C2H6O) molar mass = 2(12.01) + 6(1.01) + 16.00 = 46.08 g/mol, so 30.0 g ÷ 46.08 g/mol = 0.651 mol. Thus the chemist will use about 0.65–0.651 moles of ethanol.