A compound contains 184 g of Na and 128 g of S. What is its empirical formula? (Na = 23, S = 32)
Answer and explanation
Correct answer: A. NaS
- Step 1: Moles of Na ; moles of S .
- Step 2: Divide by the smaller number: the ratio Na : S is .
- Step 3: Empirical formula: NaS.
Answer
NaS.
Why not the others: NaS: the ratio of moles is inverted. NaS: the masses are treated as equal numbers of atoms. NaS: the ratio is not simplified correctly.
Practise more Mole Calculations.
Free questions with an explanation for every one, and full timed General Secondary Certificate (Tawjihiya Kuwait) mock tests.
More Mole Calculations questions
- Find the relative formula mass of NH. (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 40, F…
- Find the relative formula mass of MgCl. (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 40…
- Find the relative formula mass of CuSO. (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 40…
- Find the relative formula mass of Ca(NO). (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39…
- Find the relative formula mass of Fe(OH). (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 4…
- Find the relative formula mass of AgNO. (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 40…