Determine the mass of the fraction of elements in the Ca (NO3) 2 substance.

1. Let’s calculate the relative molecular weight of calcium nitrate:

Mr (Ca (NO3) 2) = 40 + 14 * 2 + 3 * 2 * 16 = 164;

2.Calculate the mass fractions of all elements in the compound:

w (Ca) = Ar (Ca): Mr (Ca (NO3) 2) = 40: 164 = 0.2439 or 24.39%;

w (N) = 2 * Ar (N): Mr (Ca (NO3) 2) = 28: 164 = 0.1707 or 17.07%;

w (O) = 2 * 3 * Ar (O): Mr (Ca (NO3) 2) = 96: 164 = 0.5854 or 58.54%;

3.Check the calculations by adding the resulting shares, as a result, it should turn out to be 100% or 1:

w (Ca) + w (N) + w (O) = 24.39% + 17.07% + 58.54% = 100%.

Answer: 24.39% Ca; 17.07% N; 58.54% O.