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3 years ago

How much of a 2.0 M NaCl solution is needed to make 205.0 mL of 0.15 M NaCl solution?

Chemistry

1 answer:

svetlana [45]3 years ago

5 0

Answer:

To relate the volume and molarity of a solution at two different concentrations, the expression used is :

M₁V₁ = M₂V₂

(2M) V₁ = (0.15M)(250ML)

V₁ = 18.75

step 3:

<h2>Pls, branliest! :)</h2>

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What is the structure of hair?

maks197457 [2]

A protective layer composed of overlapping cells, like fish scales or roof tiles, but facing downwards. The outer cuticle holds your hair in your hair follicle by means of a Velcro-like bond. It also minimizes the movement of water (moisture) in and out of the underlying cortex.

3 0

3 years ago

Read 2 more answers

Write the overall, balanced molecular equation and indicate which element is oxidized and which is reduced for the following rea

REY [17]

Explanation:

Mg(s) + Cr(C2H3O2)3 (aq)

Overall, balanced molecular equation

Mg(s) + Cr(C2H3O2)3(aq) --> Mg(C2H3O2)3(aq) + Cr(s)

To identify if an element has been reduced or oxidized, the oxidation number is observed in both the reactant and product phase.

An increase in oxidation number denotes that the element has been oxidized.

A decrease in oxidation number denotes that the element has been reduced.

Oxidation number of Mg:

Reactant - 0

Product - +3

Oxidation number of Cr:

Reactant - +3

Product - 0

Note: C2H3O2 is actually acetate ion; CH3COO- The oxidatioon number of C, H and O do not change.

Oxidized : Mg

Reduced : Cr

7 0

3 years ago

A sample of oxalic acid (a diprotic acid of the formula H2C2O4) is dissolved in enough water to make 1.00 L of solution. A 100.0

OleMash [197]

<u>Answer:</u> The mass of original oxalic acid sample is 6.75 grams

<u>Explanation:</u>

To calculate the concentration of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $H_2C_2O_4$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is NaOH.

We are given:

$n_1=2\\M_1=?M\\V_1=100.0mL\\n_2=1\\M_2=0.750M\\V_2=20.0mL$

Putting values in above equation, we get:

$2\times M_1\times 100.0=1\times 0.750\times 20.0\\\\M_1=\frac{1\times 0.750\times 20.0}{2\times 100.0}=0.075M$

To calculate the mass of solute, we use the equation used to calculate the molarity of solution:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Volume of solution (in L)}}$

Given mass of oxalic acid = ? g

Molar mass of oxalic acid = 90 g/mol

Molarity of solution = 0.075 M

Volume of solution = 1.00 L

Putting values in above equation, we get:

$0.075M=\frac{\text{Mass of oxalic acid}}{90g/mol\times 1L}\\\\\text{Mass of oxalic acid}=(0.075\times 90\times 1)=6.75g$

Hence, the mass of original oxalic acid sample is 6.75 grams

7 0

3 years ago

The half-cell is a chamber in the voltaic cell where one half-cell is the site of the oxidation reaction and the other half-cell

marysya [2.9K]

Answer:

$\boxed{\rm \text{Fe(s) $\rightleftharpoons$ Fe$^{2+}$(aq) + 2e$^{-}$}}$

Explanation:

The half-cell reduction potentials are

Ag⁺(aq) + e⁻ ⇌ Ag(s) E° = 0.7996 V

Fe²⁺(aq) + 2e⁻ ⇌ Fe(s) E° = -0.447 V

To create a spontaneous voltaic cell, we reverse the half-reaction with the more negative half-cell potential.

The anode is the electrode at which oxidation occurs.

The equation for the oxidation half-reaction is

$\boxed{\rm \textbf{Fe(s) $\rightleftharpoons$ Fe$^{2+}$(aq) + 2e$^{-}$}}$

4 0

3 years ago

Brown eye color is a dominant trait and blue eye color is a recessive trait.

Ksju [112]

Answer:

A. The person has brown eyes, and the brown eye color remains a dominant trait.

Explanation:

The dominant trait will always be the one to be show. The recessive trait will be shown if both recessive alleles are inherited.

3 0

3 years ago