What is true about water that is freezing?

Be sure to answer all parts. Calculate the pH during the titration of 30.00 mL of 0.1000 M KOH with 0.1000 M HBr solution after

Fantom [35]

Answer:

(a) pH = 12.73

(b) pH = 10.52

(c) pH = 1.93

Explanation:

The net balanced reaction equation is:

KOH + HBr ⇒ H₂O + KBr

The amount of KOH present is:

n = CV = (0.1000 molL⁻¹)(30.00 mL) = 3.000 mmol

(a) The amount of HBr added in 9.00 mL of 0.1000 M HBr is:

(0.1000 molL⁻¹)(9.00 mL) = 0.900 mmol

This amount of HBr will neutralize an equivalent amount of KOH (0.900 mmol), leaving the following amount of KOH:

(3.000 mmol) - (0.900 mmol) = 2.100 mmol KOH

After the addition of HBr, the volume of the KOH solution is 39.00 mL. The concentration of KOH is calculated as follows:

C = n/V = (2.100 mmol) / (39.00 mL) = 0.0538461 M KOH

The pOH and pH of the solution can then be calculated:

pOH = -log[OH⁻] = -log(0.0538461) = 1.2688

pH = 14 - pOH = 14 - 1.2688 = 12.73

(b) The amount of HBr added in 29.80 mL of 0.1000 M HBr is:

(0.1000 molL⁻¹)(29.80 mL) = 2.980 mmol

This amount of HBr will neutralize an equivalent amount of KOH, leaving the following amount of KOH:

(3.000 mmol) - (2.980 mmol) = 0.0200 mmol KOH

After the addition of HBr, the volume of the KOH solution is 59.80 mL. The concentration of KOH is calculated as follows:

C = n/V = (0.0200 mmol) / (59.80 mL) = 0.0003344 M KOH

The pOH and pH of the solution can then be calculated:

pOH = -log[OH⁻] = -log(0.0003344) = 3.476

pH = 14 - pOH = 14 - 3.476 = 10.52

(c) The amount of HBr added in 38.00 mL of 0.1000 M HBr is:

(0.1000 molL⁻¹)(38.00 mL) = 3.800 mmol

This amount of HBr will neutralize all of the KOH present. The amount of HBr in excess is:

(3.800 mmol) - (3.000 mmol) = 0.800 mmol HBr

After the addition of HBr, the volume of the analyte solution is 68.00 mL. The concentration of HBr is calculated as follows:

C = n/V = (0.800 mmol) / (68.00 mL) = 0.01176 M HBr

The pH of the solution can then be calculated:

pH = -log[H⁺] = -log(0.01176) = 1.93

4 0

3 years ago

Determine the molarity of a solution formed by dissolving 97.7 g libr in enough water to yield 750.0 ml of solution.

rewona [7]

Answer:

1.5 M.

Explanation:

Molarity (M) is defined as the no. of moles of solute dissolved in a 1.0 L of the solution.

<em>M = (no. of moles of LiBr)/(Volume of the solution (L).</em>

∵ no. of moles of LiBr = (mass/molar mass) of LiBr = (97.7 g)/(86.845 g/mol) = 1.125 mol.

Volume of the solution = 750.0 mL = 0.75 L.

∴ M = (no. of moles of luminol)/(Volume of the solution (L) = (1.125 mol)/(0.75 L) = 1.5 M.

3 0

3 years ago

Read 2 more answers

The reaction between sulfur dioxide and oxygen is reversible.

RUDIKE [14]

Explanation:

the correct answer is

D) 0.636 mol/dm³

3 0

2 years ago

How many valance electrons are there in group 10?

poizon [28]

there are valence electrons 3 in group 10.

5 0

2 years ago

Compounds X and Y both have the formula C7H14. Both X and Y react with one molar equivalent of hydrogen in the presence of a pal

ArbitrLikvidat [17]

Answer:

See explanation and image attached

Explanation:

Alkenes undergo hydrogenation to give the corresponding alkanes. Where the structure of the original alkene is unknown, we can deduce the structure of the alkene from the structure of the products obtained when it undergoes various chemical reactions.

Now, the fact that we obtained 2-methylhexane upon hydrogenation and the two compounds had different heats of hydrogenation means that the two compounds were geometric isomers. The original compounds must have been cis-2-methyl-3-hexene and trans-2-methyl-3-hexene.

When reacted with HCl, the same compound C7H15Cl is formed because the stereo chemistry is removed.

However, we know that the trans isomer is more stable than the cis isomer hence the cis isomer always has a higher heat of hydrogenation than the trans isomer. Thus X is cis-2-methyl-3-hexene.

4 0

3 years ago