Chemistry
What mass of copper hydroxide is precipitated by using 200 g of sodium hydroxide?
2NaOH + CuSO4 ⟶ Na2SO4 + Cu(OH)2 ↓
[Cu = 64, Na = 23, S = 32, H = 1]
Related Questions
(i) A compound has the following percentage composition by mass: carbon 14.4%, hydrogen 1.2% and chlorine 84.5%. Determine the empirical formula of this compound. Work correct to 1 decimal place. (H = 1; C = 12; Cl = 35.5)
(ii) The relative molecular mass of this compound is 168, so what is it's molecular formula?
Find the percentage of
(a) oxygen in magnesium nitrate crystals [Mg(NO3)2.6H2O].
(b) boron in Na2B4O7.10H2O. H=1,B=11,O=16,Na=23.
(c) phosphorus in the fertilizer superphosphate Ca(H2PO4)2
Solid ammonium dichromate decomposes as under:
(NH₄)₂Cr₂O₇ ⟶ N₂ + Cr₂O₃ + 4H₂O
If 63 g of ammonium dichromate decomposes. Calculate
(a) the quantity in moles of (NH₄)₂Cr₂O₇
(b) the quantity in moles of nitrogen formed.
(c) the volume of N₂ evolved at S.T.P.
(d) the loss of mass
(iv) the mass of chromium (III) formed at the same time.
Hydrogen sulphide gas burns in oxygen to yield 12.8 g of sulphur dioxide gas as under:
2H2S + 3O2 ⟶ 2H2O + 2SO2
Calculate the volume of hydrogen sulphide at S.T.P. Also, calculate the volume of oxygen required at S.T.P. which will complete the combustion of hydrogen sulphide determined in (litres).