Stoichiometry - Study Mode

[#156] The total number of atoms in 8.5 gm of NH 3 is __________ × 10 23 .
Correct Answer

(C) 12.04

Explanation

Solution: The molecular weight of NH 3 is 17 g/mol (Nitrogen = 14, Hydrogen = 1 × 3 = 3). For 8.5 grams of NH 3 , the number of moles is calculated as: Moles of NH 3 = 8.5 / 17 = 0.5 moles. The total number of molecules in 0.5 moles is: 0.5 × 6.02 × 10 23 molecules. Since each molecule of NH 3 contains 4 atoms (1 nitrogen and 3 hydrogen), the total number of atoms is: 0.5 × 6.02 × 10 23 × 4 = 12.04 × 10 23 atoms.

[#157] Which of the following holds good for a solution obeying Raoult's law (i.e., an ideal solution) (where, ΔH = heat of mixing, and ΔV = volume change on mixing ) ?
Correct Answer

(D) Both B and C

[#158] Number of gm moles of solute dissolved in 1 kg of solvent is called its
Correct Answer

(C) Molality

[#159] If pH value of a solution is 8, then its pOH value will be
Correct Answer

(A) 6

[#160] Solution made by dissolving equimolar amounts of different solutes in the same amount of a given solvent will have the
Correct Answer

(A) Same elevation in boiling point