Which of the following best captures the point of paragraph 3

Alex777 [14]

For the first one, you have to find one that has both a metal and a nonmetal in it, plus potassium. Bonds between nonmetals are called covalent because they share electrons and a bond between a metal and a nonmetal is an ionic bond because they exchange electrons.

Potassium chloride is KCl. Only an ionic bond.

Potassium hydride is KH. Only an ionic bond.

Potassium nitrate is KNO3. There we go, that has a covalent bond between the nitrogen and oxygen, and an ionic bond between potassium and the nitrogen and oxygen.

For the second one, potassium chloride is the answer because the other three also have covalent bonds. Chloride is the only one that isn't a compound.

3 0

2 years ago

A sample of Manganese (II) chloride has a mass of 19.8 grams before heating, and 12.6 grams after heating until all the water is

IRINA_888 [86]

Answer:

no. of water molecules associated to each molecule of $MnCl_2$ = 4

Explanation:

Mass of $MnCl_2$ before heating = 19.8 g

Mass of $MnCl_2$ after heating = 12.6 g

Difference in mass of $MnCl_2$ before and after heating

= 19.8 - 12.6 = 7.2 g

Difference in mass corresponds to mass of water driven out.

Molar mass of water = 18 g/mol

No. of moles of water = $\frac{7.2}{18} = 0.4\ mol$

Mass of $MnCl_2$ obtained after heating is mass of anhydrous $MnCl_2$ .

Mass of anhydrous $MnCl_2$ = 12.6 g

Molar mass of $MnCl_2$ = 125.9 g/mol

No. of mol of anhydrous $MnCl_2$ = $\frac{125.9}{125.9} = 0.1\ mol$

so,

0.1 mol of $MnCl_2$ have 0.4 mol of water

1 mol of $MnCl_2$ will have = $\frac{0.4}{0.1} =4\ mol$

Hence, no. of water molecules associated to each molecule of $MnCl_2$ = 4

5 0

3 years ago

Which matter has more attraction between the particles

julia-pushkina [17]

There are spaces between particles of matter. The average amount of empty space between molecules gets progressively larger as a sample of matter moves from the solid to the liquid and gas phases. There are attractive forces between atoms/molecules, and these become stronger as the particles move closer together.

3 0

3 years ago

Express 14.80 × 12.10 × 5.05 in scientific notation with the proper significant figures.

Naya [18.7K]

9.04354 * 10^2

The “*” identifies as a multiplication sign. Hope this helps

8 0

2 years ago

a 5L container contains 3 moles of helium and 4 moles of hydrogen at a pressure of 9 atms maintaining a constant T and additiona

Stells [14]

Answer:

7.71 atm

Explanation:

Given the following data:

$V = 5 L$

$n_{He} = 3 mol$

$n_{H_2} = 4 mol$

$p_1 = 9 atm$

$T = const$

According to the ideal gas law, we know that the product between pressure and volume of a gas is equal to the product between moles, the ideal gas law constant and the absolute temperature:

$pV = nRT$

Since the temperature and the ideal gas constant are constants, as well as the fixed container volume of 5 L, we may rearrange the equation as:

$\frac{p}{n}=\frac{RT}{V}=const$

This means for two conditions, we'd obtain:

$\frac{p_1}{n_1}=\frac{p_2}{n_2}$

Given:

$p_1 = 9 atm$

$n_1 = n_{initial total} = n_{He} + n_{H_2} = 3 mol + 4 mol = 7 mol$

$n_2 = n_{final total} = n_{He} + n_{H_2} = 3 mol + 4 mol + 2 mol = 9 mol$

Solve for the final pressure:

$p_2 = p_1\cdot \frac{n_2}{n_1}$

Now, according to the Dalton's law of partial pressures, the partial pressure is equal to the total pressure multiplied by the mole fraction of a component:

$p_{H_2}=\chi_{H_2}p_2$