All categories

3 years ago

2. Calculate the new molanty of a solution formed when 20 ml of water is added to 100 ml of

Chemistry

1 answer:

GrogVix [38]3 years ago

4 0

Answer:

New molarity = M₂ = 0.167 M

Explanation:

Given data:

New molarity = M₂ = ?

Final volume = V₂ = 100mL + 20 mL = 120 mL

Initial volume =M₁ = 100 mL

Initial molarity =V₁ = 0.2 M

Solution:

M₁V₁ = M₂V₂

0.2 M × 100 mL = M₂ × 100 mL

M₂ = 0.2 M × 100 mL/120 mL

M₂ = 20 M.mL/120 mL

M₂ = 0.167 M

You might be interested in

A certain sample of a liquid has a mass of 42 grams and a volume of 35 centimeters3. What is the density of the liquid? The dens

Xelga [282]

Density of liquid= $\frac{mass of liquid}{volume of liquid}$ .

so, density of liquid= $\frac{42 gm}{35 cm^{3} }$ = 1.2 gm/cm³.

8 0

3 years ago

Read 2 more answers

The blank is the smallest functional and structural unit of all living things.

irina [24]

The Cell is the smallest functional and structural unit of all living things

4 0

3 years ago

Read 2 more answers

An unknown solution has a pH of 7.2. Which of these chemicals is likely to cause the greatest decrease in the pH of the solution

monitta

Answer:

HNO₃.

Explanation:

It is known that acids decrease the pH of the solution, while bases increase the pH of the solution.

So, HF and HNO₃ decrease the pH of the solution as they produce H⁺ in the solution.

While, KOH and NH₃ increase the pH of the solution as they produce OH⁻ in the solution.

HNO₃ will decrease the pH of the solution greater than HF.

Because HNO₃ is strong acid that decomposes completely to produce H⁺ more than the same concentration of HF that is a weak acid which does not decomposed completely to produce H⁺.

4 0

3 years ago

Read 2 more answers

What is the h oh ph and poh of a 0.005m solution of calcium hydroxide?

fiasKO [112]

Answer: $[OH^{-}]= 0.01M or 1.0\times 10^{-2}M$

$[H^{+}]= 1.0\times 10^{-12}M$

pH = 12

pOH = 2

Explanation: Calcium hydroxide ( $Ca(OH)_{2}$ ) is a strong base that dissociates completely.

Dissociation equation of Calcium hydroxide is :

$Ca(OH)_{2} \rightarrow Ca^{+2} + 2OH^{-}$

1. Concentration of [OH-]

1 mol $Ca(OH)_{2}$ produces 2 mol OH- ions.

The given solution is 0.005M $Ca(OH)_{2}$ , then concentration of OH- would be twice the concentration of $Ca(OH)_{2}$

$[OH^{-}] = 0.005\times 2$ = 0.01M or $1.0\times 10^{-2}M$

2.Concentration of [H+]

Concentration of [H+] can be calculated by the formula: $[H^{+}] = \frac{Kw}{[OH^{-}]}$

kw = ionic product of water and its values is $(1\times 10^{-14})$

[OH-] = 0.01 M or $1.0\times 10^{-2}M$

$[H^{+}] = \frac{(1\times 10^{-14})}{[OH^{-}]}$

$[H^{+}] = \frac{(1\times 10^{-14})}{[0.01]}$

$[H^{+}] = 1.0\times 10^{-12}M$

3. pH value

pH is calculated by the formula : $pH = -log[H^{+}]$

$pH = -log[1.0\times 10^{-12}]$

pH = 12

4. pOH value

pOH is calculated by the formula : pOH = 14 - pH

pOH = 14 - 12

pOH = 2

pOH can also be calculated by using a different formula which is :

$pOH = -log(OH^{-})$

$pOH = -log(0.01)$

pOH = 2.

3 0

3 years ago

(2 pts) The solubility of InF3 is 4.0 x 10-2 g/100 mL. a) What is the Ksp? Include the chemical equation and Ksp expression. MW

Aleonysh [2.5K]

Answer:

a) Ksp = 7.9x10⁻¹⁰

b) Solubility is 6.31x10⁻⁶M

Explanation:

a) InF₃ in water produce:

InF₃ ⇄ In⁺³ + 3F⁻

And Ksp is defined as:

Ksp = [In⁺³] [F⁻]³

4.0x10⁻²g / 100mL of InF₃ are:

4.0x10⁻²g / 100mL ₓ (1mol / 172g) ₓ (100mL / 0.1L) = 2.3x10⁻³M InF₃. Thus:

[In⁺³] = 2.3x10⁻³M InF₃ × (1 mol In⁺³ / mol InF₃) = 2.3x10⁻³M In⁺³

[F⁻] = 2.3x10⁻³M InF₃ × (3 mol F⁻ / mol InF₃) = 7.0x10⁻³M F⁻

Replacing these values in Ksp formula:

Ksp = [2.3x10⁻³M In⁺³] × [7.0x10⁻³M F⁻]³ = 7.9x10⁻¹⁰

b) 0.05 moles of F⁻ produce solubility of InF₃ decrease to:

7.9x10⁻¹⁰ = [x] [0.05 + 3x]³

Where x are moles of In⁺³ produced from solid InF₃ and 3x are moles of F⁻ produced from the same source. That means x is solubility in mol / L

Solving from x:

x = -0.018 → False solution, there is no negative concentrations.

x = 6.31x10⁻⁶M → Right answer.

Thus, solubility is 6.31x10⁻⁶M

3 0

4 years ago