ANSWER THIS QUESTION PLEASE!

A scientist measures the standard enthalpy change for the following reaction to be -327.2 kJ : P4O10(s) 6 H2O(l)4H3PO4(aq) Based

OleMash [197]

Answer:

ΔH°f P4O10(s) = - 3115.795 KJ/mol

Explanation:

P4O10(s) + 6H2O(l) ↔ 4H3PO4(aq)
ΔH°rxn = ∑νiΔH°fi

∴ ΔH°rxn = - 327.2 KJ

∴ ΔH°f H2O(l) = - 285.84 KJ/mol

∴ ΔH°F H3PO4(aq) = - 1289.5088 KJ/mol

⇒ ΔH°rxn = (4)(- 1289.5088) - (6)(- 285.84) - ΔH°f P4O10(s) = - 327.2 KJ

⇒ ΔH°f P4O10(s) = - 5158.035 + 1715.04 + 327.2

⇒ ΔH°f P4O10(s) = - 3115.795 KJ/mol

5 0

4 years ago

How many grams of sodium acetate ( molar mass = 83.06 g/mol ) must be added to 1.00 Liter of a 0.200 M acetic acid solution to m

Pie

<u>Answer:</u> The mass of sodium acetate that must be added is 30.23 grams

<u>Explanation:</u>

To calculate the number of moles for given molarity, we use the equation:

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

Molarity of acetic acid solution = 0.200 M

Volume of solution = 1 L

Putting values in above equation, we get:

$0.200M=\frac{\text{Moles of acetic acid}}{1L}\\\\\text{Moles of acetic acid}=(0.200mol/L\times 1L)=0.200mol$

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[\text{salt}]}{[\text{acid}]})$

$pH=pK_a+\log(\frac{[CH_3COONa]}{[CH_3COOH]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of acetic acid = 4.74

$[CH_3COONa]=?mol$

$[CH_3COOH]=0.200mol$

pH = 5.00

Putting values in above equation, we get:

$5=4.74+\log(\frac{[CH_3COONa]}{0.200})$

$[CH_3COONa]=0.364mol$

To calculate the mass of sodium acetate for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of sodium acetate = 83.06 g/mol

Moles of sodium acetate = 0.364 moles

Putting values in above equation, we get:

$0.364mol=\frac{\text{Mass of sodium acetate}}{83.06g/mol}\\\\\text{Mass of sodium acetate}=(0.364mol\times 83.06g/mol)=30.23g$

Hence, the mass of sodium acetate that must be added is 30.23 grams

7 0

3 years ago

HCl gas is introduced at one end of the tube, and simultaneously NH3 gas is introduced at the other end. When the two gases diff

4vir4ik [10]

Answer:

When the two gases are mixed, the ammonium chloride precipitates in the tube walls.

Explanation:

This is the reaction:

HCl (g) + NH₃(g) → NH₄Cl (s) ↓

As the product formed is solid at room temperature, a suspension is first formed in the internal air of the tube that appears as a cloud. Afterwards it finally precipitates into the walls forming a white layer

5 0

3 years ago

Should the United States continue to develop/use nuclear power? Why or why not?

Vlad [161]

Answer:

Yes

Explanation:

because they should

5 0

3 years ago

A balloon is filled to a volume of 1.6 L at 278 K. The balloon is left outside overnight and the temperature has dropped to 253

german

Explanation:

Charles' law gives the relationship between the volume and the temperature of the gas. Mathematically,

Volume ∝ Temperature

i.e. $\dfrac{V_1}{V_2}=\dfrac{T_1}{T_2}$

We have, V₁ = 1.6 L, T₁ = 278 K, T₂ = 253, V₂=?

$V_2=\dfrac{V_1T_2}{T_1}\\\\V_2=\dfrac{1.6\times 253}{278}\\\\V_2=1.45\ L$

So, the new volume is 1.45 L.

6 0

3 years ago