A 1-L soda bottle contains dissolved carbon dioxide gas. Which bottle would have the highest concentration of dissolved gas?

A buffer consists of 0.120 M HNO2 and 0.150 M NaNO2 at 25°C. pka of HNO2 is 3.40. a. What is the pH of the buffer? b. What is th

Mashcka [7]

Explanation:

It is known that $K_{a}$ of $HNO_{2}$ = $4.5 \times 10^{-4}$ .

(a) Relation between $K_{a}$ and $pK_{a}$ is as follows.

$pK_{a} = -log (K_{a})$

Putting the values into the above formula as follows.

$pK_{a} = -log (K_{a})$

= $-log(4.5 \times 10^{-4})$

= 3.347

Also, relation between pH and $pK_{a}$ is as follows.

pH = $pK_{a} + log\frac{[conjugate base]}{[acid]}$

= $3.347+ log \frac{0.15}{0.12}$

= 3.44

Therefore, pH of the buffer is 3.44.

(b) No. of moles of HCl added = $Molarity \times volume$

= $11.6 M \times 0.001 L$

= 0.0116 mol

In the given reaction, $NO^{-}_{2}$ will react with $H^{+}$ to form $HNO_{2}$

Hence, before the reaction:

No. of moles of $NO^{-}_{2}$ = $0.15 M \times 1.0 L$

= 0.15 mol

And, no. of moles of $HNO_{2}$ = $0.12 M \times 1.0 L$

= 0.12 mol

On the other hand, after the reaction :

No. of moles of $NO^{-}_{2}$ = moles present initially - moles added

= (0.15 - 0.0116) mol

= 0.1384 mol

Moles of $HNO_{2}$ = moles present initially + moles added

= (0.12 + 0.0116) mol

= 0.1316 mol

As, $K_{a}$ = $4.5 \times 10^{-4}$

$pK_{a} = -log (K_{a})$

= $-log(4.5 \times 10^{-4})$

= 3.347

Since, volume is both in numerator and denominator, we can use mol instead of concentration.

As, pH = $pK_{a} + log \frac{[conjugate base]}{[acid]}$

= 3.347+ log {0.1384/0.1316}

= 3.369

= 3.37 (approx)

Thus, we can conclude that pH after the addition of 1.00 mL of 11.6 M HCl to 1.00 L of the buffer solution is 3.37.

6 0

3 years ago

4.41 g of propane gas (C3H8) is injected into a bomb calorimeter and ignited with excess oxygen, according to the reaction below

gayaneshka [121]

Answer : The heat of the reaction is -221.6 kJ

Explanation :

Heat released by the reaction = Heat absorbed by the calorimeter

$q_{rxn}=-q_{cal}$

$q_{cal}=c_{cal}\times \Delta T$

where,

$q_{rxn}$ = heat released by the reaction = ?

$q_{cal}$ = heat absorbed by the calorimeter

$c_{cal}$ = specific heat of calorimeter = $97.1kJ/^oC=97100J/^oC$

$\Delta T$ = change in temperature = $(T_{final}-T_{initial})=(27.282-25.000)=2.282^oC$

Now put all the given values in the above formula, we get:

$q_{cal}=(97100J/^oC)\times (2.282^oC)$

$q_{cal}=221582.2J=221.6kJ$

As, $q_{rxn}=-q_{cal}$

So, $q_{rxn}=-221.6kJ$

Thus, the heat of the reaction is -221.6 kJ

6 0

3 years ago

Which is more soluble at 28

CaHeK987 [17]

Answer:

a.

Explanation:

At 28 degrees highest line is CaCl2. Answer a.

3 0

3 years ago

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A period is a horizontal row on the periodic table. <br> a. True<br> b. False

Kay [80]

It is True because in the periodic table of elements, there are seven horizontal rows of elements called periods. The vertical columns of elements are called groups, or families.

6 0

3 years ago

Consider the reaction. 2c(s,graphite) h2= c2h2(g) Based on the equation and the information in the table, what is the enthalpy o

xxTIMURxx [149]

<h3>The enthalpy of the reaction : C.226.73 kJ</h3><h3>Further explanation</h3>

Delta H reaction (ΔH) is the amount of heat change between the system and its environment

(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)

The change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation

Delta H reaction (ΔH) is the difference between product enthalpy and reactant enthalpy (Hp-Hr)

Reaction :

2C + H2 -> C2H2

(ΔH) reaction = (ΔH) product - (ΔH) reactants

(ΔH) reaction = (ΔH) C2H2 - ((ΔH) C + (ΔH) H2)

for free element (ΔH) it has zero value, so (ΔH) C and (ΔH) H2 have zero value

From the available data: Hf (kJ / mol) C2 H2 (g)= 226.73

then

(ΔH) reaction = ΔH) C2H2 - ((ΔH) C + (ΔH) H2)

(ΔH) reaction = 226.73 - (0 + 0)

(ΔH) reaction = 226.73 (answer C)

<h3>Learn more</h3>

(ΔH) reaction

brainly.com/question/1889660

Keywords : (ΔH) reaction, C2H2

8 0

3 years ago

Read 2 more answers