If there are 0.064g of theobromine in a 43g chocolate bar, how many moles of theobromine are there?
If the problem is finding the moles of theobromine, then the 43 g chocolate is not really a necessary information. All you have to do is convert 0.064 g of theobromine to moles using molar mass. The molar mass of theobromine is 180.164 g/mol. So,
0.064 g (1 mol / 180.164 g) = 3.6 x10^-4 moles
The answer would be letter A or the first choice :)
Answer: \(3.5\times 10^{-4}\)
Explanation:
To calculate the moles, we use the equation:
\(\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}\)
Given mass of theobromine \((C_7H_8N_4O_2)\) = 0.064 g
Molar mass of theobromine \((C_7H_8N_4O_2)=12\times 7+1\times 8+14\times 4+16\times 2=180 g\)
\(\text{Number of moles}=\frac{0.064g}{180g/mol}=3.5\times 10^{-4}moles\)