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3 years ago

Element A has 15 protons. Determine the number of neutrons in its isotope with mass number 33.

1 answer:

6 0

In an electrically neuteral atom, number of protons = number of electrons = atomic number.
Mass number = neutrons + protons/electrons/atomic number
Therefore,
neutrons = mass number - protons/electrons/atomic number
Neutrons = 33 - 15 = 18

The answer is thus B. But this is the solution and explanation along with it as proof.

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Gas particles are pumped into a rigid steel container at a constant temperature. Which statement describes the change in pressur

Masteriza [31]

Answer:

The pressure inside the container would increase with each additional pump.

Explanation:

From the general gas law of ideal gases:

PV = nRT,

where, P is the pressure of the gas.

V is the volume of the gas.

n is the no. of moles of the gas.

R is the general gas constant.

T is the temperature of the gas.

As clear from the gas law; the pressure of the gas is directly proportional to the no. of moles of the gas.

P α n.

As gas particles are pumped into a rigid steel container, the no. of moles of the gas will increase.

So, the pressure of the gas will increase.

Thus, the right choice is: The pressure inside the container would increase with each additional pump.

8 0

3 years ago

Which of the following is NOT an example of covalent bonding? * 2 points H20 NaF NH3 O2

Pachacha [2.7K]

Answer:

I THINK NH3

Explanation:

4 0

3 years ago

Be sure to answer all parts. Dimercaprol (HSCH2CHSHCH2OH) was developed during World War I as an antidote to arsenic-based poiso

Sauron [17]

Answer:

For A: The number of arsenic atoms are $3.4\times 10^{21}$

For B: The percent composition of mercury, thallium and chromium in their complexes are 61.76 %, 62.2 % and 29.51 % respectively.

Explanation:

For A:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of dimercaprol = 696 mg = 0.696 g (Conversion factor: 1 g = 1000 mg)

Molar mass of dimercaprol = 124.21 g/mol

Putting values in above equation, we get:

$\text{Moles of dimercaprol}=\frac{0.696g}{124.21g/mol}=0.0056mol$

According to mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of molecules.

So, 0.0056 moles of dimercaprol will contain $0.0056\times 6.022\times 10^{23}=3.4\times 10^{21}$ number of molecules.

As, 1 molecule of dimercaprol binds with 1 atom of Arsenic

So, $3.4\times 10^{21}$ number of dimercaprol molecules will bind with = $1\times 3.4\times 10^{21}=3.4\times 10^{21}$ number of arsenic atoms

Hence, the number of arsenic atoms are $3.4\times 10^{21}$

For B:

We know that:

Molar mass of dimercaprol = 124.21 g/mol

Molar mass of mercury = 200.59 g/mol

Molar mass of thallium = 204.38 g/mol

Molar mass of chromium = 51.99 g/mol

Also, 1 molecule of dimercaprol binds with 1 metal atom.

To calculate the percentage composition of metal in a complex, we use the equation:

$\%\text{ composition of metal}=\frac{\text{Mass of metal}}{\text{Mass of complex}}\times 100$ ......(1)

For mercury:

Mass of Hg-complex = (200.59 + 124.21) = 324.8 g

Mass of mercury = 200.59 g

Putting values in equation 1, we get:

$\%\text{ composition of mercury}=\frac{200.59g}{324.8g}\times 100=61.76\%$

For thallium:

Mass of Tl-complex = (204.38 + 124.21) = 328.59 g

Mass of thallium = 204.38 g

Putting values in equation 1, we get:

$\%\text{ composition of thallium}=\frac{204.38g}{328.59g}\times 100=62.2\%$

For chromium:

Mass of Cr-complex = (51.99 + 124.21) = 176.2 g

Mass of chromium = 51.99 g

Putting values in equation 1, we get:

$\%\text{ composition of chromium}=\frac{51.99g}{176.2g}\times 100=29.51\%$

Hence, the percent composition of mercury, thallium and chromium in their complexes are 61.76 %, 62.2 % and 29.51 % respectively.

8 0

3 years ago

Hi! Which of the following decreases kinetic energy of solvent molecules? ( I need this handed in quickly!)

Black_prince [1.1K]

Answer:

Explanation:

4 0

3 years ago

Reacting Solutions of Aluminum Chloride with Potassium Hydroxide

gizmo_the_mogwai [7]

1Al2(SO4)3 + 3ZnCl2 → 2AlCl3 + 3ZnSO4

The coefficients represents moles. There is 1 mole of Aluminum Sulfate, 3 moles of Zinc(II) Chloride, 2 moles of Aluminum Chloride, and 3 moles of Zinc(II) Sulfate.

Now add all the coefficients/moles.

9 is the sum of all the coefficients.

7 0

2 years ago

Read 2 more answers