1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Nataly_w [17]
3 years ago
13

A solution of potassium cyanide, KCN, is made by dissolving 3.2 g of KCN in water. When this solution reacts with excess hydroch

loric acid, HCl, it produces 0.30 g of poisonous hydrogen cyanide gas, HCN.
KCN + HCl --> KCl + HCN

(a) Calculate the theoretical yield of HCN.

(b) Calculate the percent yield of HCN.
Chemistry
2 answers:
lesantik [10]3 years ago
6 0

Answer:

The theoretical yield HCN is 1.33 grams

The percent yield HCN is 22.56 %

Explanation:

Step 1: Data given

Mass of KCN = 3.2 grams

Molar mass KCN = 65.12 g/mol

Mass of HCN produced = 0.30 grams

Step 2: The balanced equation

KCN + HCl --> KCl + HCN

Step 3: Calculate moles KCN

Moles KCN = mass KCN / moalr mass KCN

Moles KCN = 3.2 grams / 65.12 g/mol

Moles KCN = 0.0491 moles

Step 4: Calculate moles HCN

For 1 mol KCN we need 1 mol HCl to produce 1 mol KCl and 1 mol HCN

For 0.0491 moles HCN we'll have 0.0491 moles HCN

Step 5: Calculate mass HCN

Mass HCN = moles HCN * molar mass HCN

Mass HCN = 0.0491 moles * 27.03 g/mol

Mass HCN = 1.33 grams = the theoretical yield

Step 6: Calculate the percent yield HCN

Percent yield = (actual yiel / theoretical yield) * 100 %

Percent yield = (0.30 grams / 1.33 grams)

Percent yield = 22.56 %

Rama09 [41]3 years ago
3 0

Answer:

22.7%

Explanation:

We must first put down the equation of reaction to guide our work while solving the problem.

KCN(aq) + HCl (aq)--> KCl(aq) + HCN(aq)

The questions specifically state that HCl is in excess so KCN is the limiting reactant.

Number of moles of KCN reacted= mass of KCN reacted / molar mass of KCN

Mass of KCN reacted= 3.2 g

Molar mass of KCN= 65.12 g/mol

Number of moles of KCN= 3.2/65.12 g/mol= 0.049 moles

Theoretical yield of HCN is obtained thus;

From the reaction equation;

1 mol of KCN produced 1 mole of HCN thus 0.049 moles of KCN will produce 0.049 moles of HCN.

Mass of HCN = number of moles ×molar mass

Molar mass of HCN= 27.0253 g/mol

Hence mass of HCN produced= 0.049mol × 27.0253 g/mol= 1.32g of HCN

Actual yield of HCN= 0.30g

% yield= actual yield/ theoretical yield ×100

% yield= 0.30/1.32 ×100

%yield= 22.7%

You might be interested in
What does the formula for water, H2O, tell you about what the molecule is made of ?
Sergeu [11.5K]

Answer:

To find out what water is made of, it helps to look at its chemical formula, which is H2O. This basically tells us that the water molecule is composed of two elements: hydrogen and oxygen or, more precisely, two hydrogen atoms (H2) and one oxygen atom (O). Hydrogen and oxygen are gases at room temperature.

Explanation:

4 0
2 years ago
2. Why should a magnesium ribbon be cleaned before burning in air ?​
Nesterboy [21]
To remove magnesium oxide layer from the ribbon which may prevent or slow down the burning of magnesium ribbon.
8 0
3 years ago
The volume of a cube is calculated by using the following formula: l x h x w. The length (l), height (h), and width (w) of a met
aliya0001 [1]

Answer:

8.909466637830

Explanation:

herp derp

8 0
2 years ago
What is the [H+] concentration of blood, given the ph is 2.5?
belka [17]

Answer:

0.00316

Explanation:

You have to use the following equation:

pH=-log[H^+]

You are given the pH and need to find the concentration of H+.  Plug in the given components and solve.

2.5=-log[H^+]\\H^+ = 10^{-2.5}\\H^+=0.00316

The concentration of H is 0.00316.

8 0
2 years ago
Which individual elements make up the following common
Sophie [7]

Answer:

I think it will carbon hope it helps

7 0
2 years ago
Other questions:
  • Suppose a student completes an experiment with an average value of 2.6 mL and a calculated standard deviation of 0.80 mL. What i
    7·1 answer
  • What is a Pure element ?
    12·1 answer
  • The water at the top of a waterfall has _____ energy.
    15·2 answers
  • Container A holds 722 mL 722 mL of an ideal gas at 2.40 atm. 2.40 atm. Container B holds 169 mL 169 mL of a different ideal gas
    5·1 answer
  • Lead is listed below zinc in the activity series.
    15·2 answers
  • The molecular weight of water, H2O, is 18.02 g over mol. How many moles of water are in 24.3 g of water? Express the answer usin
    10·1 answer
  • A is a continuous loop of moving air or liquid that transfers energy.
    9·1 answer
  • What is the mass of 2 moles of 238U?
    11·1 answer
  • The air in the inner tube of the tire of a racing bike has a pressure of 792.9 kPa. Convert this pressure to atm
    8·1 answer
  • An aqueous solution is 40.0% by mass silver nitrate, AgNO3, and has a density of 1.47 g/mL.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!