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3 years ago

Francis is learning about dissolving at school. She reads descriptions about the rate of dissolving from four of her friends.

Chemistry

2 answers:

Naddika [18.5K]3 years ago

7 0

Answer:

I personally think Manuel

Explanation:

docker41 [41]3 years ago

7 0

Um tbh in my opinion I think it’s b

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What is the maximum number of electrons that can be contained in the first, second, third, and fourth energy levels, respectivel

Natalija [7]

It can be determined by 2n^2 formula
where "n" is the no of shell:
1st shell = 2n^2 = 2(1)^2 = 2*1 = 2 electrons
2nd shell = 2n^2 = 2(2)^2 = 2*4 = 8 electrons
3rd shell = 2n^2 = 2(3)^2 = 2*9 = 18 electrons
4th shell = 2n^2 = 2(4)^2 = 2*16 = 32 electrons.

6 0

3 years ago

A 0.327-g sample of azulene (C10H8) is burned in a bomb calorimeter and the temperature increases from 25.20 °C to 27.60 °C. The

liq [111]

Explanation:

The given data is as follows.

Molecular weight of azulene = 128 g/mol

Hence, calculate the number of moles as follows.

No. of moles = $\frac{mass}{\text{molecular weight}}$

= $\frac{0.392 g}{128 g/mol}$

= 0.0030625 mol of azulene

Also, $-Q_{rxn} = Q_{solution} + Q_{cal}$

$Q_{rxn} = n \times dE$

$Q_{solution} = m \times C \times (T_{f} - T_{i})$

$Q_{cal} = C_{cal} \times (T_{f} - T_{i})$

Now, putting the given values as follows.

$Q_{solution} = 1.17 \times 10^{3} g \times 10^{3} \times 4.184 J/g^{o}C \times (27.60 - 25.20)^{o}C$

= 11748.67 J

So, $Q_{cal} = 786 J/^{o}C \times (27.60 - 25.20)^{o}C$

= 1886.4 J

Therefore, heat of reaction will be calculated as follows.

$-Q_{rxn}$ = (11748.67 + 1886.4) J

= 13635.07 J

As, $Q_{rxn} = n \times dE$

13635.07 J = $-n \times dE$

dE = $\frac{13635.07 J}{0.0030625 mol}$

= 4452267.75 J/mol

or, = 4452.26 kJ/mol (as 1 kJ = 1000 J)

Thus, we can conclude that $\Delta E$ for the given combustion reaction per mole of azulene burned is 4452.26 kJ/mol.

7 0

3 years ago

4.5 centimeters= km<br> please help me girl i’m not trying to fail science

finlep [7]

Answer:

4.5cm = 45/1000000 km

or 4.5cm= 4.5×10^-5 km.

4 0

3 years ago

Read 2 more answers

A company's managers ask, "Should we increase the size of our Bluetooth wireless speaker and sell it at a higher cost?" Never pr

Ivahew [28]

Complete Question

Identify whether the following activity on the table shown on the first uploaded image are examples of business level or corporate level strategy

Answer:

The solution to this is shown on the second uploaded image

Explanation:

The explanation is shown on the third and fourth uploaded image

5 0

3 years ago

0.50 g of hydrogen chloride (HCl) is dissolved in water to make 4.0 L of solution. What is the pH of the resulting hydrochloric

svlad2 [7]

Explanation:

Given the mass of HCl is ---- 0.50 g

The volume of solution is --- 4.0 L

To determine the pH of the resulting solution, follow the below-shown procedure:

1. Calculate the number of moles of HCl given by using the formula:

$number of moles of a substance=\frac{given mass of the substance}{its molecular mass}$

2. Calculate the molarity of HCl.

3. Calculate pH of the solution using the formula:

$pH=-log[H^+]$

Since HCl is a strong acid, it undergoes complete ionization when dissolved in water.

$HCl(aq)->H^+(aq)+Cl^-(aq)$

Thus, $[HCl]=[H^+]$

Calculation:

1. Number of moles of HCl given:

$number of moles of a substance=\frac{given mass of the substance}{its molecular mass}\\=0.50g/36.5g/mol\\=0.0137mol$

2. Concentration of HCl:

$Molarity of HCl=\frac{number of moles of HCl}{its molar mass}\\=\frac{0.0137 mol}{4.0 L} \\= 0.003425 M$

3. pH of the solution:

$pH=-log[H^+]\\=-log(0.003425)\\=2.47$

Hence, pH of the given solution is 2.47.

3 0

3 years ago