Question

please provide explanation

23) How much CNO3)2 should be weighed out to have 0.650 A) 66.4 g B) 9768 C) 107 g D) 133 E) 1653 24) How many moles of Nalios are present in a 200 g mle? A) 2.38 10-2 mol B) 1.27 - 10-2 mol C) 2.00 mol D) 850 mol E) 168 mol 25) The number of grams in 265 ml of S02 A) 265 0242 D) 170 1501034

Answer 1

23)

Molar mass of Ca(NO3)2,

MM = 1*MM(Ca) + 2*MM(N) + 6*MM(O)

= 1*40.08 + 2*14.01 + 6*16.0

= 164.1 g/mol

use:

mass of Ca(NO3)2,

m = number of mol * molar mass

= 0.65 mol * 1.641*10^2 g/mol

= 107 g

Answer: 107 g

24)

Molar mass of NaHCO3,

MM = 1*MM(Na) + 1*MM(H) + 1*MM(C) + 3*MM(O)

= 1*22.99 + 1*1.008 + 1*12.01 + 3*16.0

= 84.008 g/mol

mass(NaHCO3)= 2.00 g

use:

number of mol of NaHCO3,

n = mass of NaHCO3/molar mass of NaHCO3

=(2 g)/(84.01 g/mol)

= 2.38*10^-2 mol

Answer: A

25)

Molar mass of SO2,

MM = 1*MM(S) + 2*MM(O)

= 1*32.07 + 2*16.0

= 64.07 g/mol

use:

mass of SO2,

m = number of mol * molar mass

= 2.65 mol * 64.07 g/mol

= 170*10^2 g

Answer: D