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Which of the following chemical equations is incorrectly balanced?

A. Sb2S3 + 12HCl→ 2H3SbCl6 + 3H2S B. 3IBr + 4NH3 → NI3 + 3NH4Br C. 2KrF2 + 2H20 → 2Kr + 202 + 4HF D. PCl3 + 3H20 →... View Article

If the atomic mass of carbon were set at 50 amu, what would be the value of Avogadro’s number?

A. 5.01 × 1024 B. 6.022 × 1024 C. 1.66 × 1024 D. None of these Solution: (D) Given, Atomic mass of C = 50 amu... View Article

Aadhaar and Other Laws (Amendment) Act, 2019

Mr Ravi Shankar Prasad, Minister of Electronics and Information Technology, introduced the Aadhaar and Other Laws (Amendment) Bill 2019 in the... View Article

Choose the proper option after studying the following statement (T = True, F = False)

1. The percent composition of vinyl chloride and its polymer PVC are the same. 2. The percent composition of phosphorus trioxide (P2O3 )is... View Article

The density of Al metal is 2.7 g cm^-3. An irregularly shaped piece of aluminum weighing 40.0 g is added to a 100 mL graduated cylinder containing 50.0 mL of water. upto what height the water level will rise in the cylinder?

A. 14.8 mL B. 79.6 mL C. 64.8 mL D. 50 mL Solution: (C) d = m / v Now, V = m / d = 40 / 2.7 = 14.8 cm3 The water level in the... View Article

The unit J Pa^-1 is equivalent to;

A. m3 B. cm3 C. dm3 D. None of these Solution: (A) J / Pa = Work / Pressure = Nm / Nm-2 = m3... View Article

Haemoglobin present in blood contains 3.72% by mass iron. Calculate the number of iron atoms In 2.0 g of haemoglobin.

A. 4.53 × 1026 B. 4.53 × 1024 C. 5.95 × 1019 D. 8 × 1020 Solution: (D) Mass % of iron in haemoglobin = 3.72 %... View Article

5.5 g of a mixture of FeSO₄.7H₂O and Fe₂(SO₄)₃ 9H₂O requires 5.4 mL of 0.1N KMnO₄ solution for complete oxidation. Calculate the number of moles of Fe₂(SO₄)39H₂O in the mixture.

A. 0.0095 B. 0.15 C. 0.0952 D. 1.52 Solution: (A) Milliequivalent of KMnO4 = 5.4 x 0.1 = 0.54 milliequivalent = 0.54... View Article

In the analysis of a 0.0500 g sample of feldspar, a mixture of the chlorides of sodium and potassium is obtained, which weighs 0.1180 g. Subsequent treatment of the mixed chlorides with silver nitrate gives 0.2451 g of silver chloride. What is the percentage of sodium oxide and potassium oxide in feldspar?

(a) 10.62% Na2O, 3.58% K2O (b) 3.58% Na2O, 10.62% K2O (c) 10.62% Na2O, 35.8% K2O (d) 35.8% Na2O, 10.62% K2O Solution: (B) Suppose the... View Article

Some statements are given below based on the pictures. Identify true and false statements.

(i) ‘P’ and ‘Q’ both indicate precision and accuracy. (ii) ‘Q’ indicates precision and accuracy while... View Article

Calculate the number of sulphate ions in 100 mL of 0.001 M ammonium sulphate solution.

A. 6.022 x 10-19 B. 6.022 x 1019 C. 6.022 x 1020 D. 6.022 x 10-20 Solution: (B) No of moles of (NH4)2 SO4 = molarity x vol(L) = 0.001... View Article

Calculate the concentration of nitric acid in moles per litre in a sample that has a density of 1.41 g mL^-1 and the mass per cent of nitric acid in it being 69%.

A. 15.44 M B. 0.064 M C. 0.077 M D. 12.87 M Solution: (A) The mass per cent of 69% means that 100g of nitric acid solution containS 69... View Article

Determine the empirical formula of an oxide of iron which has 69.9% iron and 30.1% oxygen by mass.

A. FeO B. Fe2O3 C. Fe3O4 D. Fe3O2 Solution: (B) The empirical formula of a compound may be defined as the formula which gives the... View Article

Calculate the mass per cent of Na and S in sodium sulphate.

A. Na = 16.2%, S = 22.54% B. Na = 32.39%, S = 11.26% C. Na = 22.54%, S = 32.39% D. Na = 32.39%, S = 22.54% Solution: (A) Molar mass of... View Article

A naturally occurring Boron consists of two isotopes having atomic masses 10.01 and 11.01 respectively. Calculate the percentage of both the isotopes in natural Boron (Atomic mass of natural Boron = 10.81)

A. 20% and 80% B. 20% and 80% C. 25% and 75% D. 75% and 25% Solution: (A) Let x% be the percentage of an isotope with atomic weights... View Article

4.88g of KClO₃ when heated produced 1.92g of O₂ and 2.96g of KCl. Which of the following statements regarding the experiment is correct?

A. Law of conservation of mass B. Law of multiple proportions C. Law of definite proportions D. Avogadro’s Law Solution: (A)... View Article