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3 years ago

Which of the following chemical reactions is reversible?

Chemistry

2 answers:

lianna [129]3 years ago

8 0

D freezing water into ice because once the ice melts it’s water again

leva [86]3 years ago

3 0

D the freezing of water into ice

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Enough water was added to ten grams of sugar

vfiekz [6]

Answer:

25 grams (25g) of sugar

Explanation:

We can set this up algebraically:

10g = 2L

÷ 2 ÷ 2

5g = L

meaning that 5 g are needed to make 1 L

So, if we have 5 L, we will need (5 × 5) 25 grams to produce the same concentration.

6 0

2 years ago

A student has two solutions of a substance. Solution-1: 25M, 400mL, and Solution-2: 30M, 300 ml. What is the molarity of the fin

castortr0y [4]

Answer:

The molarity of the final solutions if these two solutions are mixed is 27.14 $\frac{moles}{L}$

Explanation:

Yo know:

Solution-1: 25M, 400mL
Solution-2: 30M, 300 mL

Molarity being the number of moles of solute per liter of solution, expressed by:

$Molarity (M)= \frac{number of moles}{volume}$

You can determine the number of moles that are mixed from each solution as:

Number of moles= Molarity*Volume

So, being 1 L=1000 mL, for each solution you get:

Solution-1: being 0.400 L=400 mL ⇒ 25 M* 0.400 L= 10 moles
Solution-2: being 0.300 L=300 mL ⇒ 30 M* 0.300 L= 9 moles

When mixing both solutions, it is obtained that the volume is the sum of both solutions:

Total volume= volume solution-1 + volume solution-2

and the number of total moles will be the sum of the moles of solution-1 and solution-2:

Total moles= moles of solution-1 + moles of solution-2

So the molarity of the final solution is:

$Molarity (M)= \frac{moles of solution 1 + moles of solution 2}{Volume solution 1 + Volume solution 2}$

In this case, you have:

moles of solution-1: 10 moles
moles of solution-2: 9 moles
volume solution-1: 0.400 L
volume solution-2: 0.300 L

Replacing:

$Molarity (M)=\frac{10 moles + 9 moles}{0.400 L + 0.300 L}$

Solving:

$Molarity (M)=\frac{19 moles}{0.700 L}$

Molarity= 27.14 $\frac{moles}{L}$

<u><em>The molarity of the final solutions if these two solutions are mixed is 27.14 </em></u> $\frac{moles}{L}$ <u><em></em></u>

4 0

3 years ago

When titrating a strong acid with a strong base, after the equivalence point is reached, the pH will be determined exclusively b

Arte-miy333 [17]

Answer:

B) hydroxide concentration

Explanation:

Hello,

In this case, since we are talking about strong both base and acid, since the base is the titrant and the acid the analyte, once the equivalence point has been reached, some additional base could be added before the experimenter realizes about it, therefore, since the titrant is a strong base, it completely dissociates in hydroxide ions and metallic ions which allows us to compute the pOH of the solution by known the hydroxide ions concentration.

After that, due to the fact that the pH is related with the pOH as shown below:

pH=14-pOH

We can directly compute the pH.

Best regards.

5 0

3 years ago

The first excited state of Ca is reached by absorption of 422.7 nm light. Find the energy difference (kJ/mole) between the groun

dedylja [7]

For the excited state of Ca at the absorption of 422.7 nm light,the energy difference is mathematically given as

E= 4.70x10-22 kJ/mol

<h3>What is the energy difference (kJ/mole) between the ground and the first excited state?</h3>

Generally, the equation for the Energy is mathematically given as

E = nhc / λ

Where

h= plank's constant

h= 6.625x 10-34 Js

c = speed of light

c= 3x 108 m/s

Therefore

E = 1*(6.625x 10-34 Js)( 3x 10^8 m/s) / ( 422.7x10^-9)

E= 4.70x10-22 kJ/mol

In conclusion, Energy

E= 4.70x10-22 kJ/mol

Read more about Energy

brainly.com/question/13439286

5 0

2 years ago

Give the structure of the product obtained when cyclopropene loses a proton. Will the product be aromatic or not?

astra-53 [7]

Answer:

not aromatic

Explanation:

Cyclopropene -

as the compound is is made to lose a proton , and gains a negative charge on its ring ,

Now, The ring can become aromatic or anti - aromatic depending on the number of π electrobns ,

According to Huckel 's rule ,

The cyclic compounds with ( 4n+2 ) π electrons , where , n = 0, 1, 2, 3 ... , are considered to be aromatic in nature ,

And the cyclic compounds with ( 4n ) π electrons , where , n = 1, 2, 3 ... , are considered to be anti - aromatic in nature.

Now, for the cyclopropene structure , the number of π electron are equal to 4 , 2 from the double bond and 2 from the negative charge .

Therefore , the compound becomes not aromatic or anti - aromatic .

3 0

3 years ago