All categories

1 year ago

How many moles of MgCl2 where needed to make a 650.0 mL solution a concentration of 0.962 M?

Chemistry

1 answer:

Murljashka [212]1 year ago

5 0

Answer:

0.625 moles MgCl₂

Explanation:

Since you were given a molarity value and volume, you should use the molarity equation to find moles. The equation looks like this:

Molarity (M) = moles / volume (L)

To find moles, you need to (1) convert mL to L (by dividing by 1,000) and then (2) plug the numbers into the formula and simplify to find moles. The final answer should have 3 sig figs as the lowest amount of sig figs in a given value is 3.

Step 1:

650.0 mL / 1,000 = 0.6500 L

Step 2:

Molarity = moles / volume

0.962 M = moles / 0.6500 L

(0.962 M) x (0.6500 L) = moles

0.625 = moles

You might be interested in

2. Chromium+oxygen - chromium(III) oxide balanced

sesenic [268]

Answer:

4Cr + 3O2 —> 2Cr2O3

Explanation:

Information from the question include:

Chromium + oxygen -> chromium(III) oxide

From the word equation given above, the equation can be written as follow:

Cr + O2 —> Cr2O3

The equation can be balance by doing the following:

There are 2 atoms of O on the left side and 3 atoms on the right side. It can be balance by putting 2 in front of Cr2O3 and 3 in front of O2 as shown below:

Cr + 3O2 —> 2Cr2O3

Now, we have 4 atoms of Cr on the right side and 1 atom on the left. It can be balance by putting 4 in front of Cr as shown below:

4Cr + 3O2 —> 2Cr2O3

Now the equation is balanced

3 0

2 years ago

Which of the following bases is the STRONGEST? The base is followed by its Kb.A. C6H5NH2, 4.0 × 10-10 B. NH3, 1.76 × 10-5 C. CH3

Kamila [148]

Answer:

(D) (CH3CH2)2NH

Explanation:

In order to decide which base is strongest we need to calculate its PKb

PKb = -log [Kb]

A large Kb value and small PKb value gives the strongest base

Compound Kb PKb

(A) C6H5NH2 - 4 x 10^-10 9.349

(B) NH3 1.76x 10^-5 4.754

(D) (CH3CH2)2NH 8.6x 10^-4 3.066

(E) C5H5N 1.7x10^-9 8.77

Clearly (CH3CH2)2NH is the strongest base.

3 0

2 years ago

What else is produced during the replacement reaction of silver nitrate and potassium sulfate? 2AgNO3 + K2SO4 Ag2SO4 + ________

OleMash [197]

Answer:

Explanation:

5 0

2 years ago

Read 2 more answers

Ethylene glycol (C2H6O2) is used as an antifreeze in cars. If 250 g of ethylene glycol is added to 3.00 kg of water, what is the

Zepler [3.9K]

Answer:

2,909 M

Explanation:

molair mass is of.ethylene is 26,04 g/mol

first you need to calculate how much mL 3 kg is. You can do this by using the density of ethylene: 1,1 g/mL.

3000 g x 1.1 = 3300 mL = 3,3 L

Next you need to calculate the amount of moles:

250 g / 26,04 g/mol = 9,60 mol

Now you can calculate the molarity:

9,6/3.3 = 2,909 M

I don't know the answer for the second question. I'm sorry.

3 0

2 years ago

Manganese(iv) oxide reacts with aluminum to form elemental manganese and aluminum oxide: 3mno2+4al→3mn+2al2o3part awhat mass of

Oxana [17]

12.4 g First, calculate the molar masses by looking up the atomic weights of all involved elements. Atomic weight manganese = 54.938044 Atomic weight oxygen = 15.999 Atomic weight aluminium = 26.981539 Molar mass MnO2 = 54.938044 + 2 * 15.999 = 86.936044 g/mol Now determine the number of moles of MnO2 we have 30.0 g / 86.936044 g/mol = 0.345081265 mol Looking at the balanced equation 3MnO2+4Alâ†’3Mn+2Al2O3 it's obvious that for every 3 moles of MnO2, it takes 4 moles of Al. So 0.345081265 mol / 3 * 4 = 0.460108353 mol So we need 0.460108353 moles of Al to perform the reaction. Now multiply by the atomic weight of aluminum. 0.460108353 mol * 26.981539 g/mol = 12.41443146 g Finally, round to 3 significant figures, giving 12.4 g

7 0

3 years ago