Advertisements
Advertisements
Question
Calculate the percentage of platinum in ammonium chloroplatinate (NH4)2PtCl6.
[N = 14, H = 1, Pt = 195, Cl =35.5]
(Give your answer correct to the nearest whole number)
Advertisements
Solution
Molecular formula of ammonium chloroplatinate (NH4)2PtCl6 :
2 x (atomic mass of N + 8 x atomic mass of H) + atomic mass of platinum + 6 x atomic mass of chlorine
2 x (14 + 8 ) + 195 + 6 x 35.3= 444
444 parts of ammonium chloroplatinate contains 195 parts by weight of platinum
So, 100 parts will contain = 195 x 100/444 = 43.9‰ = 44‰
APPEARS IN
RELATED QUESTIONS
Define the term:
Vapour density
Calculate the percentage of water in ferrous sulphate crystals.
[Fe = 56, S = 32, O =16, H = 1].
When heated, potassium permanganate decomposes according to the following equation:
\[\ce{2KMnO4 -> \underset{solid residue}{K2MnO4 + MnO2} + O2}\]
Given that the molecular mass of potassium permanganate is 158 g, what volume of oxygen (measured at room temperature) would be obtained by the complete decomposition of 15.8 g of potassium permanganate? (Molar volume at room temperature is 24 litres). [K = 39, Mn = 55, O = 16]
Calculate the percentage of nitrogen in aluminium nitride. [Al = 27, N = 14]
The equation for the burning of octane is:
\[\ce{2C6H18 + 25O2 -> 16CO2 + 18H2O}\]
If the relative molecular mass of carbon dioxide is 44, what is the mass of carbon dioxide produced by burning two moles of octane?
Give one word or phrase for the following:
The ratio of the mass of a certain volume of gas to the mass of an equal volume of hydrogen under the same conditions of temperature and pressure.
Complete the following calculations. Show working for complete credit :
If the empirical formula of a compound is CH and it has a vapour density of 13, find the molecular formula of the compound.
Calculate the relative molecular mass of:
(NH4)2SO4
Correct the statement, if required.
Under similar conditions of temperature and pressure, two volumes of hydrogen combined with two volumes of oxygen will give two volumes of water vapour.
When heated, potassium permanganate decomposes according to the following equation :
\[\ce{2KMnO4 -> \underset{\text{solid residue}}{K2MnO4 + MnO2} + O2}\]
(a) Some potassium permanganate was heated in the test tube. After collecting one litre of oxygen at room temperature, it was found that the test tube had undergone a loss in mass of 1.32 g. If one litre of hydrogen under the same conditions of temperature and pressure has a mass of 0.0825 g, calculate the relative molecular mass of oxygen.
(b) Given that the molecular mass of potassium permanganate is 158. What volume of oxygen (measured at room temperature) would be obtained by the complete decomposition of 15.8 g of potassium permanganate? (Molar volume at room temperature is 24 litres)
