Basic Concepts of Chemistry

How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g of HCl?

The percentage weight of Zn in white vitriol [ZnSO₄ 7H₂O] is approximately equal to Zn=65, S=32, O=16 and H=1)

One litre hard water contains 12 mg Mg²⁺. Milli equivalents of washing soda required to remove its hardness is

0.45 g acid of molecular weight 90 was neutralise by 20 mL of 0.5 N KOH. The basicity of acid is

At S.T.P the density of CCl₄ vapours in g/L will be nearest to

1.520 g of hydroxide of a metal on ignition gave 0.995 g of oxide. The equivalent weight of metal is

Boron has two stable isotopes, ¹°B(19%) and ¹¹B(81%). Average atomic weight for boron in the periodic table is

The density of air is 0.001293 g/cc at STP. Its vapour density is

If the equivalent weight of an element is 32, then the percentage of oxygen in its oxide is

What is the equivalent weight of SnCl₂ in the following reaction, SnCl₂+Cl₂→ SnCl₄?

The number of moles of KMnO₄ that will be needed to react with one mole of sulphite ion in acidic solution is

6.02 x 10²⁰ molecules of urea are present in 100 mL of its solution. The concentration of the solution is

What is the [OH⁻] in the final solution prepared by mixing 20 mL of 0.05 M Hcl with 30 mL of 0.1 M Ba(OH)₂?

Assuming fully decomposed, the volume of CO₂ released at STP on heating 9.85 g of BaCO₃(Atomic mass Ba=137) will be

The number of oxygen atoms in 4.4g of CO₂ is

If 1 mL of water contains 20 drops then number of molecules in a drop of water is

The weight of one molecule of a compound C₆₀H₁₂₂ is

An aqueous solution of glucose is 10% in strength. The volume in which 1 g mole of it is dissolved will be

The number of atoms in 0.1 mol of a triatomic gas is (Na = 6.02 x 10²³ mol⁻¹)

The maximum number of molecules is present in

A 5 molar solution of H₂SO₄ is diluted from 1 liter to a volume of 10 litres, the normality of the solution will be

If Nₐ is Avagadro number then number of valence electrons in 4.2g of nitride ions (N³⁻) is

³⁵₁₇Cl and ³⁷₁₇Cl are two isotopes of chlorine. If average atomic weight is 35.5 then ratio of these two isotopes is

Volume occupied by one molecule of water (density= 1 g cm⁻³) is

The number of significant figures for the three numbers 161 cm, 0.161 cm, 0.0161 cm are

Mass of one atom of X is 2.66 x 10⁻²³ g, then its 32 g is equal to

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

The weight of iron which will be converted into its oxide(Fe₃O₄) by the action of 18 g of steam on it will be (at. wt. of Fe=56)

The number of gram molecules of oxygen in 6.02 x 10²⁴ CO molecules is

If 30 mL of H₂ and 20 mL of O₂ reacts to form water. what is left at the end of the reaction?

Ratio of Cₚ and Cᵥ of the gas X is 1.4. The number of atoms of the gas X present in 11.2 litres of it at NTP will be

A mixture contains O₂ and N₂ in the ratio of 1 : 4 by the weight. The ratio of their number of moles is

Which has the maximum number of molecules among the following

What is the weight of oxygen required for the complete combusion of 2.8 kg of ethylene?

1 c.c N₂O at NTP contains

A bromoalkane contains 35% carbon and 6.57% hydrogen by mass. Calculate the empirical formula of this bromoalkane.

An organic compound containing C, H and O gave the following analysis:
C=40%; H=6.66%; Its empirical formula would be

An organic compound containing C, H, N gave the following analysis: C=40%; H=13.33%; N=46.67%. Its empirical formula would be

Copper occurs naturally as Cu-63 and Cu-65. Given Atomic Weight of Carbon is 63.546, Which isotope is more abundant?

The number of moles of KMnO₄ reduced by one mole of Kl in alkaline medium is

Haemoglobin contains 0.334% of iron by weight. The molecular weight of haemoglobin is approximately 67200. The number of iron atoms (Atomic Weight of Fe is 56) present in one molecule haemoglobin are

In a sample of 400 lithium atoms, it is found that 30 atoms are lithium-6 (6.015 g/mol) and 370 atoms are lithium-7 (7.016 g/mol). Calculate the average atomic mass of lithium

A metal oxide has the formula Z₂O₃. It can be reduced by hydrogen to give free metal and water. 0.1596 of the metal oxide requires 6 mg of hydrogen for complete reduction. The atomic weight of the metal is

The isotopic abundance of C-12 and C-14 is 98% and 2% respectively. What would be the number of C-14 isotopic in 12 g carbon sample?

Percentage of Se in peroxidase anhydrase enzyme is 0.5% by weight(at. wt= 78.4) then minimum molecular weight of peroxidase anhydrase enzyme is

In haber process 30 litres of dihydrogen and 30 litres of dinitrogen were taken for reaction which yielded only 50% of the expected product. What will be composition of gaseous mixture under the aforesaid condition in the end?

A sample of element X contains 100 atoms with a mass of 12.00 and 10 atoms with a mass of 14.00. Calculate the average atomic mass (in amu) of element X.

Specific volume of cylindrical virus particle is 6.02 x 10⁻² cc/gm whose radius and length 7 Å and 10 Å respectively. If N = 6.02 x 10²³, find molecular weight of virus

An element, X has the following isotopic composition ²°°X:90% , ¹⁹⁹X:8%, ²°²X:2%
The weighted average atomic mass of the naturally occuring element X is closest to

The molecular weight of O₂ and SO₂ are 32 and 64 respectively. At 15C and 150mm Hg pressure, one litre of O₂ contains N molecules. The number of molecules in two litres of SO₂ under the same conditions of temperature and pressure will be

What volume of oxygen gas measured at 0°C and 1 atm, is needed to burn completely 1L of propane gas (C₃H₈) measured under the same conditions?

Concentrated aqueous sulpuric acid is 98% H₂SO₄ by mass and has a density of 1.8 g mL⁻¹. Volume of acid required to make one litre of 0.1 MH₂SO₄ soln is

Liquid benzene C₆H₆ burns in oxygen according to the equation
2C₆H₆ (l)+15O₂ (g) → 12CO₂ (g) + 6H₂O(g)
How many litres of O₂ at STP are needed to complete the combustion of 39 g of liquid benzene? Mol.Wt of O₂=32, C₆H₆=78)

The mass of carbon anode consumed(giving only carbon-dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall Process is (At wt of Al=27)

In the reaction
4NH₃ (g) + 5O₂ (g) → 4NO (g) + 6H₂O (l)
When 1 mole of ammonia and 1 mole of O₂ are made to react to completion

There are two naturally-occuring isotopes of carbon: C-12 (12.0 amu) and C-13 (13.0 amu). If you select one hundred carbon atoms at random, what would the total mass be? Consider abundance of C-12 is very high.

A compound is found to contain 50.05 % sulfur and 49.95 % oxygen by weight. The molecular weight for this compound is 64.07 g/mol. What is its molecular formula?

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