Students in science are studying solutions and the dissolving rate of solids. One group was given some instant lemonade mix to

A barium hydroxide solution is prepared by dissolving 2.06 g of Ba(OH)2 in water to make 32.9 mL of solution. What is the concen

navik [9.2K]

Answer: 1.36 M

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

$Molarity=\frac{n\times 1000}{V_s}$

where,

n = moles of solute

To calculate the moles, we use the equation:

moles of solute= $\frac{\text {given mass}}{\text {molar mass}}=\frac{2.06g}{171g/mol}=0.0120moles$

$Molarity=\frac{0.0120\times 1000}{32.9}=0.364M$

The balanced reaction between barium hydroxide and perchloric acid:

$2HCIO_4+Ba(OH_)2\rightarrow BaCIO_4+2H_2O$

To calculate the concentration of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $HClO_4$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is $Ba(OH)_2$

We are given:

$n_1=1\\M_1=?\\V_1=8.50mL\\n_2=2\\M_2=0.364M\\V_2=15.9mL$

Putting values in above equation, we get:

$1\times M_1\times 8.50=2\times 0.364\times 15.9\\\\M_1=1.36M$

Thus the concentration of the acid is 1.36 M

4 0

3 years ago

2.17 in to 10^23 molecules of Br 2 to moles

KiRa [710]

I don't get what you are saying... Can you reword it?

3 0

3 years ago

Jean and her mother were taking a walk when they saw the two rocky outcrops in the diagram below.

Veseljchak [2.6K]

Answer:

you have to attach the diagram

Explanation:

5 0

2 years ago

A negative △H means an exothermic reaction. True False

Nostrana [21]

Your answer is False I think

6 0

3 years ago

When 3.93 grams of lactic acid, CHoOs(s), are burned in a bomb

aliya0001 [1]

The heat released in the combustion of lactic acid is absorbed by the

calorimeter and in the decomposition of the lactic acid.

ΔH°f of lactic acid is approximately -716.2 kJ

Reasons:

Known parameters are;

Mass of the lactic acid = 3.93 grams

Heat capacity of the bomb calorimeter = 10.80 kJ·K⁻¹

Change in temperature of the calorimeter, ΔT = 5.34 K

ΔHrxn = ΔErxn

ΔH°f of H₂O(l) = -285.8 kJ·mol⁻¹

ΔH°f of CO₂(g) = -393.5 kJ·mol⁻¹

The chemical equation for the reaction is presented as follows;

C₃H₆O₃ + 2O₂ → 3CO₂ + 3H₂O

The heat of the reaction = 10.80 kJ·K⁻¹ × 5.34 K = 57.672 kJ

Molar mass of C₃H₆O₃ = 90.07 g/mol

Number of moles of C₃H₆O₃ = $\dfrac{3.93 \, g}{90.07 \, g/mol}$ = 0.043633 moles

Number of moles of CO₂ produced = 3 × 0.043633 moles = 0.130899 moles

Heat produced = 0.130899 mole × -285.8 kJ·mol⁻¹ = -37.4109342 kJ

Moles of H₂O produced = 0.130899 moles

Heat produced = 0.130899 mole × -393.5 ≈ -51.51 kJ

Therefore, we have;

Heat absorbed by the lactic acid = ΔH°f of H₂O + ΔH°f of CO₂ + Heat absorbed by the calorimeter

Which gives;

Heat absorbed by lactic acid = -37.4109342 kJ - 51.51 kJ + 57.672 kJ ≈ -31.249 kJ

The heat absorbed by the lactic acid ≈ -31.249 kJ

$\Delta H^{\circ}f \ of \ C_3H_6O_3 = \dfrac{-31.249}{0.043633} \approx -716.2$

ΔH°f of C₃H₆O₃ ≈ -716.2 kJ

Heat of formation of lactic acid ≈ -716.2 kJ.

Learn more here:

brainly.com/question/13185938

5 0

2 years ago