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Elenna [48]
4 years ago
10

5g of a mixture of KOH and KCl with water form a solution of 250mL. We have 25ml of this solution and we mix it with 14,3mL of H

Cl 0,1M. What's the % of the inicial mixture?
The 14,3mL of HCl are necessary to neutralize the KOH.

What are the reactions and what do I need to calculate?
Chemistry
1 answer:
cricket20 [7]4 years ago
7 0
We know that the number of moles HCl in 14.3mL of 0.1M HCl can be found by multiplying the volume (in L) by the concentration (in M).
(0.0143L HCl)x(0.1M HCl)=0.00143 moles HCl

Since HCl reacts with KOH in a one to one molar ratio (KOH+HCl⇒H₂O+KCl), the number of moles HCl used to neutralize KOH is the number of moles KOH. Therefore the 25mL solution had to contain 0.00143mol KOH.

To find the mass of KOH in the original mixture you have to divide the number of moles of KOH by the 0.025L to find the molarity of the KOH solution..
(0.00143mol KOH)/(0.025L)=0.0572M KOH

Since the morality does not change when you take some of the solution away, we know that the 250mL solution also had a molarity of 0.0572.  That being said you can find the number of moles the mixture had by multiplying 0.0572M KOH by 0.250L to get the number of moles of KOH.
(0.0572M KOH)x(0.250L)=0.0143mol KOH

Now you can find the mass of the KOH by multiplying it by its molar mass of 56.1g/mol.
0.0143molx56.1g/mol=0.802g KOH

Finally you can calulate the percent KOH of the original mixture by dividing the mass of the KOH by 5g.
0.802g/5g=0.1604
the original mixture was 16% KOH

I hope this helps.

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Which of these compounds hast the highest melting point <br> CCl4<br> CBr4<br> CH4<br> CF4<br> CI4
ikadub [295]

The compound CBr4 has the highest melting point of 91°C

4 0
4 years ago
Since water can be prepared in the laboratory
Arturiano [62]

Answer:

# In a familiar high-school chemistry demonstration, an instructor first uses electricity to split water into its constituent gases, Hydrogen and Oxygen. Then, by combining the two gases and igniting them with a spark, the instructor changes the gases back into water with a loud pop (That means the energy is released in the process).

# There are new other ways to produce water in laboratory, however, the scientists can not produce water in large quantity for the masses, because of some reasons.

1- Theoretically, this is possible, but it would be an extremely dangerous process. Since Hydrogen is extremely flammable and Oxygen supports combustion, it wouldn’t take much to create this force, but we also have an explosion. That’s why this process can be a deadly one if our experiment is big enough.

2- Personally, I think that it makes no sense to produce water in a laboratory ( or in a large plant) for people to use as daily water. The much more important thing we need to do is to save our environment, our planet Earth. Because the daily water people drink contains not just water molecules but other minerals, the marine life is depend not just in water molecules but diferent factors, etc.

Explanation:

This is just my personal opinion. Hope that can help you a little. Have a nice day

7 0
3 years ago
A truck travels 110 miles and it speed is 55mi/hr. How long did it take to
hammer [34]

Answer:

2 hours Speed =110/2=55 miles ler hour

4 0
3 years ago
(You do) If you have 47.2 mol of Na available, along with an excess of Cl₂, how many grams of NaCl can you produce?
IrinaVladis [17]

Answer:

2,760 grams NaCl

Explanation:

To find grams of NaCl, you need to (1) convert moles of Na to moles of NaCl (via mole-to-mole ratio from reaction) and (2) convert moles of NaCl to grams (via molar mass from periodic table). The final answer should have 3 significant figures based on the given measurement.

2 Na + Cl₂ --> 2 NaCl

Molar Mass (NaCl) = 22.99 g/mol + 35.45 g/mol

Molar Mass (NaCl) = 58.44 g/mol

47.2 moles Na           2 moles NaCl              58.44 grams

----------------------  x  ---------------------------  x  -------------------------  =
                                   2 moles Na                   1 mole NaCl

= 2,758.368 grams NaCl

= 2,760 grams NaCl

5 0
2 years ago
The hot dogs you ate at the barbecue last week were 75% fat-free by weight, had 275 calories, and weighed 110 g. a) What percent
vovangra [49]

Answer:

a) 25%

b) 27.5 g

c) 90%

Explanation:

a) 75% fat-free by weight means 25% of the weight is made by fat.

b) 110 g ___ 100%

      x    ___ 25%

          x = 27.5g

Each hot dog has 27.5g of fat.

c) 9 cal ___ 1 g fat

      y    ___ 27.5 g fat

          y = 247.5 cal

275 cal ___ 100%

247.5 cal ___ z

     z = 90%

90 % of the calories come from fat.

6 0
3 years ago
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