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When 2.25 g of sodium hydroxide (NaOH) was dissolved in 150.00 g of water a value of 11.00oC was obtained for ΔT.1. Calculate the molarity of the sodium hydroxide solution.
2. Calculate the value (calories) for the heat of solution of 2.25 g of NaOH.
3. Calculate the number of calories that would be produced if one mole of sodium hydroxide was dissolved. (ΔHsolnNaOH)

Answers

Answer 1

Answer:

Answer:

For 1: The molarity of sodium hydroxide solution is 0.375 M

For 2: The amount of heat absorbed by solution is 1674.75 Cal

For 3: The enthalpy change of the reaction when 1 mole of NaOH is dissolved is 1674.75 Cal

Explanation:

For 1:

To calculate mass of a substance, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

Density of water = 1 g/mL

Mass of water = 150.00 g

Putting values in above equation, we get:

$1g/mL=\frac{150.00g}{\text{Volume of water}}\n\n\text{Volume of water}=(1g/mL* 150.00g)=150.00mL$

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}* 1000}{\text{Molar mass of solute}* \text{Volume of solution (in mL)}}$

We are given:

Mass of solute (sodium hydroxide) = 2.25 g

Molar mass of sodium hydroxide = 40 g/mol

Volume of solution = 150.00 mL

Putting values in above equation, we get:

$\text{Molarity of solution}=(2.25g* 1000)/(40g/mol* 150mL)\n\n\text{Molarity of solution}=0.375M$

Hence, the molarity of sodium hydroxide solution is 0.375 M

For 2:

To calculate the amount of heat absorbed, we use the equation:

$q=mc\Delta T$

where,

m = mass of solution = (2.25 + 150) = 152.25 g

c = specific heat capacity of water = 1 Cal/g.°C

$\Delta T$ = change in temperature = 11°C

Putting values in above equation, we get:

$q=152.25g* 1Cal/g.^oC* 11^oC\n\nq=1674.75Cal$

Hence, the amount of heat absorbed by solution is 1674.75 Cal

For 3:

To calculate the enthalpy change of the reaction, we use the equation:

$\Delta H_(rxn)=(q)/(n)$

where,

$q$ = amount of heat absorbed = 16

74.75 Cal

n = number of moles = 1 mole

$\Delta H_(rxn)$ = enthalpy change of the reaction

Putting values in above equation, we get:

$\Delta H_(rxn)=(1674.75Cal)/(1mol)=1674.75Cal/mol$

Hence, the enthalpy change of the reaction when 1 mole of NaOH is dissolved is 1674.75 Cal

Answer 2

Answer:

Final answer:

The molarity of the sodium hydroxide is 0.375 M. The heat of solution of the sodium hydroxide is -1650 cal, and the heat of solution per mole of sodium hydroxide is -29333.33 cal/mol.

Explanation:

To answer your questions, we first need to convert the mass of the sodium hydroxide (NaOH) to moles. Sodium hydroxide has a molar mass of approximately 40 g/mol, so 2.25 g is 0.05625 mol.

1. The molarity of the solution is the number of moles of solute per liter of solution. Given that the solution was made up in 150.00 g of water, which is approximately 0.150 L (since the density of water is approximately 1 g/mL), the molarity is 0.05625 mol / 0.150 L = 0.375 M.

2. The heat of solution can be calculated using the equation q = m * c * ΔT, where m is the mass of the water, c is the specific heat capacity of the water (approximately 1 cal/g°C), and ΔT is the change in temperature. Plugging in the known values, q = 150.00 g * 1 cal/g°C * 11°C = 1650 cal. This is the heat absorbed by the water and so the heat of solution of NaOH is -1650 cal (as the process of dissolving is exothermic).

3. The heat of solution per mole of sodium hydroxide can be calculated by dividing the total heat of solution by the number of moles of sodium hydroxide. So ΔHsoln NaOH = -1650 cal / 0.05625 mol = -29333.33 cal/mol.

Learn more about Thermodynamics and Stoichiometry here:

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questions with regards to this reaction.
a) Write the molecular equation for this reaction by
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Answers

Answer:

2 FeBr₃(aq) + 3 (NH₄)₂CO₃(aq) = Fe₂(CO₃)₃(s) + 6 NH₄Br(aq)

Explanation:

Aqueous solutions of iron(III) bromide and ammonium carbonate react. This is a double displacement reaction that gives place to ammonium bromide and iron (III) carbonate. Iron (III) carbonate is insoluble so it precipitates. The corresponding molecular equation is:

2 FeBr₃(aq) + 3 (NH₄)₂CO₃(aq) = Fe₂(CO₃)₃(s) + 6 NH₄Br(aq)

Consider the neutralization reaction 2HNO3(aq) + Ba(OH)2 ( aq ) ⟶ 2H2O ( l ) + Ba ( NO3)2 ( aq ). A 0.125 L sample of an unknown HNO 3 solution required 32.3 mL of 0.200 M Ba ( OH ) 2 for complete neutralization. What is the concentration of the HNO 3 solution?

Answers

Answer:

The concentration of the HNO3 solution is 0.103 M

Explanation:

Step 1: Data given

Volume of the unknow HNO3 sample = 0.125 L

Volume of 0.200 M Ba(OH)2 = 32.3 mL = 0.0323 L

Step 2: The balanced equation

2HNO3(aq) + Ba(OH)2 ( aq ) ⟶ 2H2O ( l ) + Ba( NO3)2 (aq)

Step 3:

n2*C1*V1 = n1*C2*V2

⇒ n2 = the number of moles of Ba(OH)2 = 1

⇒ C1 = the concentration of HNO3 = TO BE DETERMINED

⇒ V1 = the volume of the HNO3 solution = 0.125 L

⇒ n1 = the number of moles of HNO3 = 2

⇒ C2 = the concentration of Ba(OH)2 = 0.200 M

⇒ V2 = the volume of Ba(OH)2 = 0.0323 L

1*C1 * 0.125 L = 2*0.200M * 0.0323 L

C1 = (2*0.200*0.0323)/0.125

C1 = 0.103 M

The concentration of the HNO3 solution is 0.103 M

Show the conversion factor from Patolbf/ft2is 0.02089.

Answers

Explanation:

1 Pascal = 1 N/m²

To convert Pa to lbf/ft²

So, the conversion of N to pound force (lbf) is shown below as:

1 N = 0.224809 pound force (lbf)

The conversion of m² to ft² is shown below:

1 m² = 10.7639 ft²

So,

[tex]1\ Pa=\frac {1\ N}{1\ m^2}=\frac {0.224809\ lbf}{10.7639\ ft^2}

1 Pa = 0.02089 lbf / ft²

Hence proved.

How many grams of Cl are in 31.2g CF2Cl2

Answers

Answer:

Mass = 42.6 g

Explanation:

Given data:

Mass of CF₂Cl₂ = 31.2 g

Mass of Cl₂ = ?

Solution:

Number of moles of CF₂Cl₂ = mass/molar mass

Number of moles = 31.2 g/121 gmol

Number of moles = 0.3 mol

1 mole of CF₂Cl₂ contain 2 moles of Cl atom.

0.3 mol × 2 = 0.6 mol

Mass of Cl₂:

Mass = number of moles × molar mass

Mass = 0.6 mol × 71 g/mol

Mass = 42.6 g

A substance that cannot be chemically broken down into simpler substances is a an electron. b a heterogeneous mixture. c an element. d a homogeneous mixture. e a compound.

Answers

Answer:

c. an element.

Explanation:

An element -

It refers to the substance , which has same type of atoms , with exactly same number of protons , is referred to as an element .

In term of chemical species , elements are the smallest one , and can not be bifurcated down to any further small substance by the means of any chemical reaction .

Hence , from the given information of the question ,

The correct term is an element .

Answer:

C. an element.

Explanation:

Estimate how much heat in joules is released when 25.0 g of water (C = 4.184 J/g°C) is cooled from 80.0°C to 30.0°C?