The density of a 2 M aqueous solution of NaOH is 1.28 g/. The molality of the solution is:
[molecular mass of NaOH = 40 ]
1. | 1.20 m | 2. | 1.56 m |
3. | 1.67 m | 4. | 1.32 m |
ln, a closed vessel, 50 ml of completely reacts with 200 ml of C2 according to the following equation:
The composition of the gaseous mixture in the system will be:
1. 100 ml
2. 25 ml
3. 75 ml
4. 10 ml
On complete combustion, 44 g of a sample of a compound gives 88 g CO2 and 36 g of H2O. The molecular formula of the compound may be:
1.
2.
3.
4.
1. | 40 mol | 2. | 10 mol |
3. | 20 mol | 4. | 30 mol |
An organic compound contains carbon, hydrogen, and oxygen. Its elemental analysis gave C, 38.71%, and H, 9.67%. The empirical formula of the compound would be:
1. | CH3O | 2. | CH2O |
3. | CHO | 4. | CH4O |
The volume of oxygen gas (O2) needed to completely burn 1 L of propane gas (C3H8) (both O2 & propane measured at 0°C and 1 atm) will be:
1. 7 L
2. 6 L
3. 5 L
4. 10 L
25.3 g of sodium carbonate, Na2CO3, is dissolved in enough water to make 250 mL of a solution. If sodium carbonate completely dissociates, the molar concentrations of sodium ion, Na+ and carbonate ion, are respectively:
(molar mass of Na2CO3 = 106g mol-1)
1. 0.955 M and 1.910 M
2. 1.910 M and 0.955 M
3. 1.90 M and 1.910 M
4. 0.477 M and 0.477 M
The maximum number of molecules is present in which of the following?
1. 15 L of gas at STP
2. 5 L of gas at STP
3. 0.5 g of gas
4. 10 g of gas
The number of moles present in 2.5 litres of 0.2 M are:
1. 0.25
2. 0.5
3. 0.75
4. 0.2
The number of valence electrons present in 0.53 grams of Na2CO3 is:
1.
2.
3.
4.