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k,S04 (aq) +2H20 (1) K 34,102 32, oc O lex4 5) Solid potassium hydroxide reactin

ID: 717160 • Letter: K

Question

k,S04 (aq) +2H20 (1) K 34,102 32, oc O lex4 5) Solid potassium hydroxide reacting with sulfuric acid to produce aqueous potassium 1 74. sulfate and liquid water. a. If 25.g of sulfuric acid is reacted with 7.7 g of potassium hydroxide, how many grams of potassium sulfate are produced?SC of excess reactant that remains after the reaction is completed. would you expect to obtain if the reaction has a 47.2% yield? b. For part (a) of this problem, identify the limiting reactant and calculate the mass c. From your theoretical yield calculated in part (a), how many grams of material

Explanation / Answer

a)

Molar mass of KOH,

MM = 1*MM(K) + 1*MM(O) + 1*MM(H)

= 1*39.1 + 1*16.0 + 1*1.008

= 56.108 g/mol

mass(KOH)= 7.7 g

use:

number of mol of KOH,

n = mass of KOH/molar mass of KOH

=(7.7 g)/(56.11 g/mol)

= 0.1372 mol

Molar mass of H2SO4,

MM = 2*MM(H) + 1*MM(S) + 4*MM(O)

= 2*1.008 + 1*32.07 + 4*16.0

= 98.086 g/mol

mass(H2SO4)= 25.0 g

use:

number of mol of H2SO4,

n = mass of H2SO4/molar mass of H2SO4

=(25.0 g)/(98.09 g/mol)

= 0.2549 mol

Balanced chemical equation is:

2 KOH + H2SO4 ---> K2SO4 + 2 H2O

2 mol of KOH reacts with 1 mol of H2SO4

for 0.1372 mol of KOH, 6.862*10^-2 mol of H2SO4 is required

But we have 0.2549 mol of H2SO4

so, KOH is limiting reagent

we will use KOH in further calculation

Molar mass of K2SO4,

MM = 2*MM(K) + 1*MM(S) + 4*MM(O)

= 2*39.1 + 1*32.07 + 4*16.0

= 174.27 g/mol

According to balanced equation

mol of K2SO4 formed = (1/2)* moles of KOH

= (1/2)*0.1372

= 6.862*10^-2 mol

use:

mass of K2SO4 = number of mol * molar mass

= 6.862*10^-2*1.743*10^2

= 11.96 g

Answer: 12.0 g

b)

KOH is limiting reagent

According to balanced equation

mol of H2SO4 reacted = (1/2)* moles of KOH

= (1/2)*0.1372

= 6.862*10^-2 mol

mol of H2SO4 remaining = mol initially present - mol reacted

mol of H2SO4 remaining = 0.2549 - 6.862*10^-2

mol of H2SO4 remaining = 0.1863 mol

Molar mass of H2SO4,

MM = 2*MM(H) + 1*MM(S) + 4*MM(O)

= 2*1.008 + 1*32.07 + 4*16.0

= 98.086 g/mol

use:

mass of H2SO4,

m = number of mol * molar mass

= 0.1863 mol * 98.09 g/mol

= 18.27 g

Answer: 18.3 g

c)

% yield = actual mass*100/theoretical mass

47.2= actual mass*100/11.96

actual mass=5.644 g

Answer: 5.64 g