Question

Determine the molecular weight for mg(no3)2.

134.32 g

118.32 g

148.33 g

172.64 g

Answer 1

Molecular Weight (MW) is the sum of the atomic weights/masses (AM) of every atom in a compound or molecule. Thus, we would add the AM of Mg + 2×[N+(O×3)]:
Mg = 24.31
N = 14.01
O = 16
So we have: Mg + 2×[N+(O×3)] = 24.31 + 2×[14.01+(16×3)] = 24.31+2×[14.01+48] = 24.31+ 2×62.01 = 24.31+124.02 = 148.33

C) is the correct answer

Answer 2

Answer: The correct answer is 148.33 grams.

Step-by-step explanation:

To calculate the molecular weight of a compound, we add on the mass of individual atoms are added multiplies with the number of individual atoms present.

Calculating the mass of
`Mg(NO_3)_2`:

Mass of magnesium = 24.305 g/mol

Mas of nitrogen = 14.007 g/mol

Mass of oxygen = 15.999 g/mol

Mass of
`Mg(NO_3)_2=[24.305+(2* 14.007)+(6* 15.999)]=148.33g/mol`

1 mole of magnesium nitrate has a mass of 148.33 grams.

Hence, the correct answer is 148.33 grams.