Recent questions tagged some-basic-concepts-of-chemistry

4.5 gm of solute having molar mass of 90 gm/mol is dissolved in water to make 250 ml solution. Calculate molarity of the solution Numerical Value Type

One mole of carbon atom weighs 12 g, the number of atoms in it is equal to, (Mass of carbon-12 is 1.9926 × 10–23 g) (1) 6.022 × 1023 (2) 1.2 × 1023 (3) 6.022 × 1022 (4) 12 × 1022

The ration of the mass percentages of 'C & H' and 'C & O' of a saturated acyclic organic compound 'X' are 4 : 1 and 3 : 4 respectively. Then, the moles of oxygen gas required for complete combustion of two moles of organic compound 'X' is____. Numerical ...

Specific volume of cylindrical virus particle is 6.02 × 10-2 cc/g whose radius and length are 7 Å and 10 Å respectively. If NA = 6.02 × 1023, find molecular weight of virus. (a) 15.4 kg/mol (b) 1.54 × 104 kg/mol (c) 3.08 × 104 kg/mol (d) 3.08 × 103 kg/mol

Molarity of liquid HCl, if density of solution is 1.17 g/cc is (a) 36.5 (b) 18.25 (c) 32.05 (d) 42.10

Percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (at. wt. = 78.4) then minimum molecular weight of peroxidase anhydrous enzyme is (a) 1.568 × 104 (b) 1.568 × 103 (c) 15.68 (d) 2.136 × 104

Which has maximum molecules? (a) 7 g N2 (b) 2 g H2 (c) 16 g NO2 (d) 16 g O2

The maximum number of molecules is present in (a) 15 L of H2 gas at STP (b) 5 L of N2 gas at STP (c) 0.5 g of H2 gas (d) 10 g of O2 gas.

An element, X has the following isotopic composition: 200X : 90% 199X : 8.0% 202X : 2.0% The weighted average atomic mass of the naturally occurring element X is closest to (a) 201 amu (b) 202 amu (c) 199 amu (d) 200 amu

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 (a) CHO (b) CH4O (c) CH3O (d) CH2O

How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g HCl? (a) 0.011 (b) 0.029 (c) 0.044 (d) 0.333

What volume of oxygen gas (O2) measured at 0°C and 1 atm, is needed to burn completely 1 L of propane gas (C3H8) measured under the same conditions? (a) 5 L (b) 10 L (c) 7 L (d) 6 L

10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reaction will be (a) 3 mol (b) 4 mol (c) 1 mol (d) 2 mol

25.3 g of sodium carbonate, $\require{mhchem}\ce{Na2CO3}$ is dissolved in enough water to make 250 mL of solution. If sodium carbonate dissociates completely, molar concentration of sodium ion, $\ce{Na+}$ and carbonate ions, $\ce{CO3^2-}$ are respectively (...

The number of atoms in 0.1 mol of a triatomic gas is (NA = 6.02 × 1023 mol-1) (a) 6.026 × 1022 (b) 1.806 × 1023 (c) 3.600 × 1023 (d) 1.800 × 1022

Which has the maximum number of molecules among the following? (a) 44 g CO2 (b) 48 g O3 (c) 8 g H2 (d) 64 g SO2

In an experiment it showed that 10 mL of 0.05 M solution of chloride required 10 mL of 0.1 M solution of AgNO3, which of the following will be the formula of the chloride (X stands for the symbol of the element other than chlorine) (a) X2Cl2 (b) XCl2 (c) ...

6.02 × 1020 molecules of urea are present in 100 mL of its solution. The concentration of solution is (a) 0.001 M (b) 0.1 M (c) 0.02 M (d) 0.01 M

1.0 g of magnesium is burnt with 0.56 g O2 in a closed vessel. Which reactant is left in excess and how much? (At. wt. Mg = 24, O = 16) (a) Mg, 0.16 g (c) Mg, 0.44 g (b) O2, 0.16 g (d) O2, 0.28 g

When 22.4 litres of H2(g) is mixed with 11.2 litres of Cl2(g), each at S.T.P, the moles of HCl(g) formed is equal to (a) 1 mol of HCl(g) (b) 2 mol of HCl(g) (c) 0.5 mol of HCl(g) (d) 1.5 mol of HCl(g).

Equal masses of H2, O2 and methane have been taken in a container of volume V at temperature 27 °C in identical conditions. The ratio of the volumes of gases H2 : O2 : methane would be (a) 8 : 16 : 1 (b) 16 : 8 : 1 (c) 16 : 1 : 2 (d) 8 : 1 : 2

A mixture of gases contains H2 and O2 gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two gases in the mixture? (a) 16 : 1 (b) 2 : 1 (c) 1 : 4 (d) 4 : 1

The number of water molecules is maximum in (a) 1.8 gram of water (b) 18 gram of water (c) 18 moles of water (d) 18 molecules of water.

If Avogadro number NA, is changed from 6.022 1023 mol-1 to 6.022 1020 mol-1, this would change (a) the mass of one mole of carbon (b) the ratio of chemical species to each other in a balanced equation (c) the ratio of elements to each other in a ...

What is the mass of the precipitate formed when 50 mL of 16.9% solution of AgNO3 is mixed with 50 mL of 5.8% NaCl solution? (Ag = 107.8, N = 14, O = 16, Na = 23, Cl = 35.5) (a) 3.5 g (b) 7 g (c) 14 g (d) 28 g

Suppose the elements $X$ and $Y$ combine to form two compounds $XY_2$ and $X_3Y_2$. When $0.1$ mole of $XY_2$ weighs $10\ g$ and $0.05$ mole of $X_3Y_2$ weighs $9\ g$, the atomic weights of $X$ and $Y$ are (a) $40,\ 30$ (b) $60,\ 40$ (c) $20,\ 30$ (d) $30,\...

A solution of sodium sulfate contains 92 g of Na+ ions per kilogram of water. The molality of Na+ ions in that solution in mol kg–1 is: (1) 16 (2) 8 (3) 4 (4) 12

The number of moles of hydrogen molecules required to produce 20 moles of ammonia through Haber's process is : (1) 10 (2) 20 (3) 30 (4) 40