Advertisements
Advertisements
प्रश्न
Calculate the percentage of boron (B) in borax (Na2B4O7.10H2O). [H = 1, B = 11, O = 16, Na = 23],
answer correct to 1 decimal place.
Advertisements
उत्तर
Molecular mass of borax Na2B4O7.10H2O = 382
382 parts by weight of borax contain 44 parts by weight of boron
So,100 parts will contain = 44 x 100/382 = 11.5‰
Percentage of boron (B) in borax (Na2B4O7.10H2O) = 11.5‰.
APPEARS IN
संबंधित प्रश्न
Prove the Following :
2 X V.D. = Molecular mass.
Calculate the relative molecular mass of Ammonium sulphate.
(use K = 39, Cl = 35.5, O = 16, C = 12, H = 1, Na = 23, N = 14, S= 32)
Fill in the blank.
Molecular weight of a gas is twice its __________.
Potassium nitrate on strong heating decomposes as under :
2KNO3 → 2KNO2 + O2
Calculate : Weight of potassium nitrite formed.
(K = 39, 0 = 16, N = 14)
10g of NaCl solution is mixed with 17g of silver nitrate solution. Calculate the weight of silver chloride precipitated.
AgNO3 + NaCl → AgCI + NaNO3
Chlorine, nitrogen, ammonia and sulphur dioxide gases are collected under the same conditions of temperature and pressure.
Copy the following table which gives the volumes of the gases collected, and the number of molecules (X) in 20L of nitrogen.You are to complete the table by giving the number of molecules in th e other gases, in terms of X.
| Gas | Volume(litres) | Number of molecules |
| Chlorine | 10 | |
| Nitrogen | 20 | X |
| Ammonia | 20 | |
| Sulphur dioxide | 5 |
Calculate the relative molecular mass of:
Ammonium chloroplatinate (NH4)2 PtCl6
Calculate the relative molecular mass of:
(NH4)2 Cr2O7
Find the weight of 0.2 mole of H2 gas.
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.
