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प्रश्न
Calculate the percentage of phosphorous in the fertilizer superphosphate, Ca(H2PO4)2. [Ca = 40, H =1, P =31, O = 16] (Correct to 1 decimal place)
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उत्तर
Molecular mass of fertilizer superphosphate, Ca(H2PO4)2 =234
234 parts by weight of fertilizer contains 62 parts by weight of phosphorous
So, 100 parts will contain = 62 x 100/234 = 26.5‰
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संबंधित प्रश्न
Aluminium carbide reacts with water according to the following equation :
`Al_4C_3 + 12H_2O-> 4Al(OH)_3 + 3CH_4`
1)What mass of aluminium hydroxide is formed from 12g of aluminium carbide?
2) What volume of methane at s.t.p. is obtained from 12g of aluminium carbide?
[Relatively molecular weight of `Al_4Cl_3 = 144; Al(OH)_3 = 78]`
Calculate the relative molecular mass of Chloroform.
(use K = 39, Cl = 35.5, O = 16, C = 12, H = 1, Na = 23, N = 14, S= 32)
When excess lead nitrate solution was added to a solution of sodium sulphate, 15.1g of lead sulphate was precipitated. What mass of sodium sulphate was present in the original solution?
Na2SO4 + Pb(NO3)2 → PbSO4 + 2NaNO3
(H = 1, C = 12, O = 16, Na = 23, S = 32, Pb = 207)
Samples of the gases O2, N2, CO2 and CO under the same conditions of temperature and pressure contain the same number of molecules represented by X. The molecules of Oxygen, occupy V litres and have a mass of 8 g. Under the same conditions of temperature and pressure :
What is the mass of CO2 in g?
The reaction of potassium permanganate (VII) with acidified iron (II) sulphate is given below:
2KMno4 + 10FeSO4 + 8H2O → K2SO4 + 2MnSO4 + 5Fe2(SO4)3 + 8H2O
If 15.8g of potassium permanganate (VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction.
A gaseous hydrocarbon contains 82.76% of carbon. Given that its vapour density is 29, find its molecular formula.
[C = 12, H = 1]
Calculate the relative molecular mass of:
(NH4)2SO4
Calculate the relative molecular mass of:
CHCl3
What do you understand by the statement that ‘vapour density of carbon dioxide is 22’?
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)
