Is an oreo a pure substance or a mixture and why?

When dissolving a solid or liquid, as the temperature of the solvent increases, the rate of dissolution?

Alinara [238K]

Answer:A. Increases

Explanation:

Heating or an increase in temperature increases the kinetic energy of particles thereby increasing their motion and how they relate and react with one another.

Increase in the temperature of the solvent is directly proportional to the rate of dissolution. The rate of dissolution increases due to the increase in kinetic energy. This makes the solvent particles interact faster with the solute particles thereby increasing the dissolution rate.

7 0

3 years ago

Explain what the purpose of a gene is!!!!<br><br> *20*

Nataliya [291]

Answer:

The purpose of genes is to store information. Each gene contains the information required to build specific proteins needed in an organism.

Explanation:

8 0

3 years ago

Read 2 more answers

A student increases the temperature of a 417cm³ balloon from 278k to 231k. Assuming constant pressure, what should the new volum

viva [34]

Charles law states that volume of gas is directly proportional to temperature at constant pressure
V/T = k
where V - volume , T - temperature and k - constant
$\frac{V1}{T1} = \frac{V2}{T2}$
where parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation

in the question it states that the temperature has been increased from 278 K to 231 K but it should actually be temperature is decreased from 278 K to 308 K
substituting the values in the equation
$\frac{417cm^{3} }{278K} = \frac{V}{308 K}$
V = 462 cm³
the answer should be D. 462 cm³

3 0

3 years ago

On the basis of periodic trends, choose the larger atom from each pair (if possible): match the elements in the left column to t

Ne4ueva [31]

The given question is incomplete. The complete question is as follows.

On the basis of periodic trends, choose the larger atom from each pair (if possible): match the elements in the left column to the appropriate blanks in the sentences on the right. make certain each sentence is complete before submitting your answer.

Sn, F, Ge, not predictable, Cr

Of Ge or Po, the larger atom is .........

Of F or Se, the larger atom is ..........

Of Sn or I, the larger atom is .........

Of Cr or W, the larger atom is ........

Explanation:

When we move down a group then there occurs an increase in atomic size of the atoms due to increase in the number of electrons.

Ge is a group 14 element which lies in period 4 and Po is a group 16 element that lies in period 6. As polonium is larger in size as compared to germanium.

Fluorine is a group 17 element and lies in period 2. Selenium is a group 16 element lies in 4. Therefore, selenium is larger in size as compared to fluorine.

Sn is a group 14 element that lies in period 5 and I is a group 17 element that lies in period 5. Hence, I is a larger atom.

Cr is a d-block element which lies in period 4 and W is also a d-block element which lies in period 6. Hence, W is larger in size than Cr.

Thus, we can conclude that given blanks are matched as follows.

Of Ge or Po, the larger atom is Po.

Of F or Se, the larger atom is Se.

Of Sn or I, the larger atom is I.

Of Cr or W, the larger atom is W.

7 0

3 years ago

What is the Ka of a 0.0796 M solution of nitrous acid (HNO2) with a pH of 2.95?

Vadim26 [7]

Answer:

Coefficient = 1.58

Exponent = - 5

Explanation:

pH = 2.95

Molar concentration = 0.0796M

Ka = [H+]^2 / [HA]

Ka = [H+]^2 / 0.0796

Therefore ;

[H+] = 10^-2.95

[H+] = 0.0011220 = 1.122 × 10^-3

Ka = [H+] / molar concentration

Ka = [1.122 × 10^-3]^2 / 0.0796

Ka = (1.258884 × 10^-6) / 0.0796

Ka = 15.815 × 10^-6

Ka = 1.58 × 10^-5

Coefficient = 1.58

Exponent = - 5

4 0

3 years ago