All categories

3 years ago

What mass of K2CO3 is needed to prepare 200. mL of a solution having a potassium ion concentration of 0.150 M

Chemistry

1 answer:

I am Lyosha [343]3 years ago

4 0

Answer:

2.07 grams

Explanation:

We know that the molecular mass of $K_2CO_3$ is 138.205 grams.

In order to find out how many grams we need to make 200 mL having a potassium ion concentration of 0.150, we need to find the number of moles first.

M = moles / liters

0.150 = x / 0.200

x = 0.03 moles

Since there are 2 potassium atoms in each molecule of $K_2CO_3$ so we will divide this number by half and multiply it by the molecular mass.

0.03/2 = 0.015 moles

Mass of $K_2CO_3$ needed = 0.015 × 138.205 = 2.07 grams

You might be interested in

How many atoms of nitrogen (N) are found in (NH4)2CO3 have

sammy [17]

It has 2 nitrogens. This is because there is 1 nitrogen in the ammonium, and there are two ammonium molecules.

8 0

4 years ago

Can someone pleaseeeeeeeeeee check my work to see if I did it right?

Jet001 [13]

Answer:

Its right!

Explanation:

6 0

3 years ago

Indicate which solution in each pair has the lower pH. Your response should be a four letter "word". The first letter should be

JulijaS [17]

Answer:

bcfh

Explanation:

HClO₄ reacts with water thus:

HClO₄ + H₂O → H₃O⁺ + ClO₄⁻

That means HClO₄ produce H₃O⁺ that decreases pH. That means the higher concentration of HClO₄ decreases pH. Thus, lower pH will be:

b) 0.2 M HClO4

The reaction of NaClO₄ is:

NaClO₄ + H₂O → OH⁻ + HClO₄ + Na⁺

The higher concentration of NaClO₄ the higher production of OH⁻ that increase pH, that means the lower concentration of NaClO₄ the lower pH, thus, the answer is:

c) 0.1 M NaClO or

HF reacts with water thus;

HF ⇄ H⁺ + F⁻

The equilibrium constant is:

k = [H⁺] [F⁻] / [HF] = 3,5x10⁻⁴

For HNO₂ equilibrium is:

HNO₂ ⇄ H⁺ + NO₂⁻

k = [H⁺] [NO₂⁻] / [HNO₂] = 4,5x10⁻⁴

As k value is higher for HNO₂, the concentration of H⁺ will be higher in this system doing the HNO₂ with the lower pH.

f) 0.1 M HNO2

NaOH is a strong base that produce OH⁻ that increase pH, pure water is neutral, thus, the lowe pH is:

h) pure water

I hope it helps!

7 0

4 years ago

Please help!!!

3241004551 [841]

Answer:

1.) The result is a red solution and a blue-green precipitate.

2.) The reaction results in a precipitate of a basic salt, which can co-precipitate with other metal ions that form hydroxide precipitates, causing complications when trying to separate metal ions.

6 0

3 years ago

Read 2 more answers

In the first 15.0 s of the reaction, 1.9×10−2 mol of O2 is produced in a reaction vessel with a volume of 0.480 L . What is the

N76 [4]

The question is incomplete, here is the complete question:

Consider the following reaction: $2N_2O(g)\rightarrow 2N_2(g)+O_2(g)$

In the first 15.0 s of the reaction, 1.9×10⁻² mol of O₂ is produced in a reaction vessel with a volume of 0.480 L . What is the average rate of the reaction over this time interval?

Answer: The average rate of appearance of oxygen gas is $2.64\times 10^{-3}M/s$