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3 years ago

Plzz help me with these questions....!!!

Chemistry

1 answer:

exis [7]3 years ago

7 0

Answer:-

1) The pH of sodium bicarbonate will be around 8 as it is slightly basic. So the color will be blue.

2) The correct method for finding the pH of a solution is to use a dropper and drop wise add the solution to the pH paper lying on a glass tile. Hence the answer is 3.

3) HCl is an acid. The pH of HCl should be 1-2. NaOH is a base. It’s pH should be around 13-14.

KCl is a salt of a strong acid and strong base. It should have pH near 7. Distilled water has pH of 7. So the solutions with equal pH are KCl and distilled water. So the answer is number 4 (B and D).

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What occurs in solvation

Lynna [10]

By an IUPAC definition, solvation is an interaction of a solute with the solvent, which leads to stabilization of the solute species in the solution. In the solvated state, an ion in a solution is surrounded or complexed by solvent molecules. ... Solvation or dissolution is a kinetic process and is quantified by its rate.

7 0

3 years ago

Compare the type of change that occurs when a substance melts and when a substance is set on fire. Use complete sentences to jus

Amiraneli [1.4K]

When a substance melts it has changed from a solid to a liquid state while when a substance is set on fire is changes from liquid to gaseous state as it boils.

<h3>What is change of state?</h3>

Change of state of matter is the transformation of a substance from one phase of matter to another.

When a substance melts it has changed from a solid to a liquid state while when a substance is set on fire is changes from liquid to gaseous state as it boils.

Learn more about matter here:

brainly.com/question/3998772

#SPJ1

8 0

2 years ago

Read 2 more answers

Which of the following are cations? Check all that apply.

Lostsunrise [7]

Answer:

barium

calcium

aluminum

magnesium

copper

Forms cation

Explanation:

4 0

3 years ago

H2O has a mc021-1.jpgHvap = 40.7 kJ/mol. What is the quantity of heat that is released when 27.9 g of H2O condenses?

jekas [21]

The molecular weight of H2O is 18g/mol.
Therefore, 27.9 g H2O / (1mol/18g) = 0.155 mol H2O
Calculating only for the latent heat, the heat required to be released for this amount of H2O to condense is:
40.7 kJ/mol (0.155 mol) = 6.3 kJ or -6.3 kJ since it is to be released

8 0

3 years ago

Read 2 more answers

a) Calculatethe molality, m, of an aqueous solution of 1.22 M sucrose, C12H22O11. The density of the solution is 1.12 g/mL.b) Wh

Contact [7]

Answer:

a) 1,74 molal

b) 37,2 %

c) 0,03

Explanation:

We are going to define sucrose as solute, water as solvent and the mix of both, the solution.

Let´s start with the data:

$Molarity = M = \frac{1,22 mol solute}{lts solution}$

We can assume as a calculus base, 1 liter of solution. So, in 1 liter of solution we have 1,22 moles of solute:

$1 lts solution * \frac{1,22 moles solute}{lts solution}=1,22 moles solute$

Knowing that the molality (m) is defined as mol of solute/kgs solvent, we have to calculate the mass of solvent on the solution. Remember our calculus base (1 lts of solution). In 1 lts of solution we have 1120 grams of solution.

$1 lts solution * \frac{1,12 grs solution}{mL solution}*\frac{1000 mL solution}{1 lts solution} = 1120 grs of solution$

With the molecular weight of solute (<em>Sum of: for carbon = 12*12=144; for hydrogen = 1*22=22 and for oxygen = 16*11=176. Final result = 342 grs per mol</em>), we can obtain the mass of solute:

$1,22 mol solute*\frac{342 grs solute}{1 mol solute} = 417,24 grs solute$

Now, the mass of solvent is: mass solvent = mass of solution - mass of solute. So, we have: 1120 - 417,24 = 702,76 grs of solvent = 0,70276 Kgs of solvent

$molality = m = \frac{1,22 mol solute}{0,70276 kgs solvent}= 1,74 molal$

For b) question we have that the mass percent of solute is hte ratio between the mass of solute and the mass of solution. So,

$%(w/w) = \frac{417,24 grs solute}{1120 grs solution} = 37,2%$

For c) question we have that the mole fraction of solute is the ratio between moles of solute and moles of solution. Let's calculate the moles of solution as follows: <em>Moles solution = moles solute + moles solvent.</em> First we have that the moles of solvent are (remember that the molecular weight of water for this calculus is 18 grs per mol):

$702,76 grs solvent*\frac{1 mol solvent}{18 grs solvent} = 39,04 moles solvent$

So, we have the moles of solution: 1,22 moles of solute + 39,04 moles of solvent = 40,26 moles of solution

Finally, we have:

$Mol frac solute = \frac{1,22 mol solute}{40,26 mol solution}= 0,03$

6 0

3 years ago