1) Calculate the molarity of a solution produced by dissolving 35.7 g of solid Cu(ClO3)2 in enough water to make 250 mL of solution. 2) How many moles of SnCO3 are in 317.4 mL of a 0.75M solution?

1. 0.62M

2. 0.24mol

Explanation:

Molarity (M) = number of moles (n) ÷ volume (V)

1.) According to this question, 35.7 g of solid Cu(ClO3)2 was dissolved in water to make 250mL solution.

Molar mass of Cu(ClO3)2 where Cu = 63.5, Cl = 35.5, O = 16 is;

63.5 + {35.5 + 16(3)}2

63.5 + {35.5 + 48}2

63.5 + {83.5}2

63.5 + 167

= 230.5g/mol

Using mole = mass/molar mass

mole = 35.7/230.5

= 0.1548

= 0.155mol

Volume = 250mL = 250/1000 = 0.250L

Molarity = number of moles ÷ volume

Molarity = 0.155 ÷ 0.250

Molarity = 0.62M

2.) Molarity = number of moles ÷ volume

number of moles = Molarity × volume

Volume of SnCO3 solution = 317.4 mL = 317.4/1000 = 0.3174 L

number of moles (n) = 0.75M × 0.3174 L

n = 0.238

n = 0.24mol

Decreasing order is as follows:

γ-rays > x-rays > red light > infrared > radio

Explanation:

Energy and wavelength are inversely related with each other.

In other words, energy decreases as the wavelength of electromagnetic radiation increases.

Order of wavelength for the given radiations are as follows:

Radio > infrared > red light > x-rays > γ-rays

So, order of the energy will be reverse.

γ-rays > x-rays > red light > infrared > radio