The solution

A sample of 9.27 g9.27 g of solid calcium hydroxide is added to 38.5 mL38.5 mL of 0.500 M0.500 M aqueous hydrochloric acid. Writ

navik [9.2K]

Answer: The excess reagent for the given chemical reaction is calcium hydroxide and the amount left after the completion of reaction is 0.115375 moles. The amount of calcium chloride formed in the reaction is 1.068 grams.

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ....(1)

For calcium hydroxide:

Given mass of calcium hydroxide = 9.27 g

Molar mass of calcium hydroxide = 74.093 g/mol

Putting values in above equation, we get:

$\text{Moles of calcium hydroxide}=\frac{9.27g}{74.093g/mol}=0.125mol$

To calculate the moles of a solute, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

We are given:

Volume of hydrochloric acid = 38.5mL = 0.0385 L (Conversion factor: 1 L = 1000 mL)

Molarity of the solution = 0.500 moles/ L

Putting values in above equation, we get:

$0.500mol/L=\frac{\text{Moles of hydrochloric acid}}{0.0385L}\\\\\text{Moles of hydrochloric acid}=0.01925mol$

For the given chemical equation:

$2HCl(aq.)+Ca(OH)_2(s)\rightarrow CaCl_2(s)+2H_2O(l)$

Here, the solid salt is calcium chloride.

By Stoichiometry of the reaction:

2 moles of hydrochloric acid reacts with 1 mole of calcium hydroxide.

So, 0.01925 moles of hydrochloric acid will react with = $\frac{1}{2}\times 0.01925=0.009625moles$ of calcium hydroxide.

As, given amount of calcium hydroxide is more than the required amount. So, it is considered as an excess reagent.

Thus, hydrochloric acid is considered as a limiting reagent because it limits the formation of product.

Amount of excess reagent (calcium hydroxide) left = 0.125 - 0.01925 = 0.115375 moles

By Stoichiometry of the reaction:

2 moles of hydrochloric acid produces 1 mole of calcium chloride.

So, 0.01925 moles of hydrochloric acid will produce = $\frac{1}{2}\times 0.01925=0.009625moles$ of calcium chloride.

Now, calculating the mass of calcium chloride from equation 1, we get:

Molar mass of calcium chloride = 110.98 g/mol

Moles of calcium chloride = 0.009625 moles

Putting values in equation 1, we get:

$0.009625mol=\frac{\text{Mass of calcium chloride}}{110.98g/mol}\\\\\text{Mass of calcium chloride}=1.068g$

Hence, the excess reagent for the given chemical reaction is calcium hydroxide and the amount left after the completion of reaction is 0.115375 moles. The amount of calcium chloride formed in the reaction is 1.068 grams.

5 0

3 years ago

Read 2 more answers

Which of these electron transitions correspond to absorption of energy and which to emission?

Keith_Richards [23]

The electron transitions representing absorption of energy are:

(a) n = 2 to n = 4

(d) n = 3 to n = 4

and those which represents emissions of energy are:

(b) n = 3 to n = 1

(c) n = 5 to n = 2

An electron emits energy when it jumps from a higher energy level to a lower energy level transitions.

An electron absorbs energy to jump from a lower energy level to a higher energy level transitions.

(a) n = 2 to n = 4

Here, the initial level (2) is lower than the final level (4).

Hence energy is absorbed.

(b) n = 3 to n = 1

Here, the initial level (3) is higher than the final level (1).

Hence energy is released.

(c) n = 5 to n = 2

Here, the initial level (5) is higher than the final level (2).

Hence energy is released.

(d) n = 3 to n = 4

Here, the initial level (3) is lower than the final level (4).

Hence energy is absorbed.

The question is incomplete. Find the complete question here:

Which of these electron transitions correspond to absorption of energy and which to emission?

(a) n = 2 to n = 4

(b) n = 3 to n = 1

(c) n = 5 to n = 2

(d) n = 3 to n = 4

Learn more about electron transitions at brainly.com/question/2079874

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4 0

2 years ago

Complete the sentence. The higher the hydrogen ion concentration, the ______ the pH.

arsen [322]

The answer would be lower because the higher the pH is he lower the number is

7 0

3 years ago

Read 2 more answers

Calculate the pH after 0.018 mole of HCl is added to 1.00 L of each of the four solutions. (Assume that all solutions are at 25°

Over [174]

Explanation:

Below are attachments containing the solution

7 0

3 years ago

A gas of unknown molecular mass was allowed to effuse through a small opening under constant-pressure conditions. It required 10

masya89 [10]

Answer: The molar mass of unknown gas is 367.12 g/mol

Explanation:

Rate of a gas is defined as the amount of gas displaced in a given amount of time.

$\text{Rate}=\frac{V}{t}$

To calculate the rate of diffusion of gas, we use Graham's Law.

This law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows the equation:

$\text{Rate of effusion}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}$

So,

$\left(\frac{\frac{V_{X}}{t_{X}}}{\frac{V_{O_2}}{t_{O_2}}}\right)=\sqrt{\frac{M_{O_2}}{M_{X}}}$

We are given:

Volume of unknown gas (X) = 1.0 L

Volume of oxygen gas = 1.0 L

Time taken by unknown gas (X) = 105 seconds

Time taken by oxygen gas = 31 seconds

Molar mass of oxygen gas = 32 g/mol

Molar mass of unknown gas (X) = ? g/mol

Putting values in above equation, we get:

$\left(\frac{\frac{1.0}{105}}{\frac{1.0}{31}}\right)=\sqrt{\frac{32}{M_X}}\\\\M_X=367.12g/mol$

Hence, the molar mass of unknown gas is 367.12 g/mol

3 0

4 years ago