Question

State the number of moles in 20g of Cu(NO3)2.

A) 0.1 moles
B) 0.2 moles
C) 0.5 moles
D) 1 mole

Answer 1

To determine the number of moles in 20g of Cu(NO3)2, divide the mass by the molar mass of the compound. The resulting answer is approximately 0.1 moles.

Step-by-step explanation:

To determine the number of moles in 20g of Cu(NO3)2, we need to use the molar mass of Cu(NO3)2. The molar mass of Cu(NO3)2 is calculated by adding up the atomic masses of each element in the compound. The atomic mass of Cu is 63.55 g/mol, the atomic mass of N is 14.01 g/mol, and the atomic mass of O is 16.00 g/mol. Multiplying the atomic masses by the number of atoms in each element, we get:

63.55 g/mol * 1 (Cu atom) = 63.55 g/mol

14.01 g/mol * 2 (N atoms) = 28.02 g/mol

16.00 g/mol * 6 (O atoms) = 96.00 g/mol

Adding up the masses, we get:

63.55 g/mol + 28.02 g/mol + 96.00 g/mol = 187.57 g/mol

Now, we can use the molar mass to calculate the number of moles:

Number of moles = Mass / Molar mass

Number of moles = 20g / 187.57 g/mol = 0.106 moles

Therefore, the number of moles in 20g of Cu(NO3)2 is approximately 0.1 moles (Option A).