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3 years ago

9

Which phrase accurately describes the location of Africa? O mostly in the eastern hemisphere mostly south of the Tropic of Capri

corn O borders the Pacific Ocean O lies north of Europe

1 answer:

dimaraw [331]3 years ago

5 0

Answer:

mostly in the eastern hemisphere mostly south of the Tropic of Capricorn

Explanation:

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A mixture of nitrogen and hydrogen gases, at a total pressure of 663 mm Hg, contains 3.46 grams of nitrogen and 0.156 grams of h

STALIN [3.7K]

<u>Answer:</u> The partial pressure of nitrogen gas is 405.76 mmHg and that of hydrogen gas is 257.24 mmHg

<u>Explanation:</u>

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

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

<u>For nitrogen gas:</u>

Given mass of nitrogen gas = 3.46 g

Molar mass of nitrogen gas = 28 g/mol

Putting values in above equation, we get:

$\text{Moles of nitrogen gas}=\frac{3.46g}{28g/mol}=0.123mol$

<u>For hydrogen gas:</u>

Given mass of hydrogen gas = 0.156 g

Molar mass of hydrogen gas = 2 g/mol

Putting values in above equation, we get:

$\text{Moles of hydrogen gas}=\frac{0.156g}{2g/mol}=0.078mol$

Mole fraction of a gas is calculated by using the formula:

$\chi_{A}=\frac{n_{A}}{n_{A}+n_{B}}$ ......(1)

<u>For nitrogen gas:</u>

Putting values in equation 1, we get:

$\chi_{\text{nitrogen gas}}=\frac{0.123}{0.123+0.078}=0.612$

<u>For hydrogen gas:</u>

Putting values in equation 1, we get:

$\chi_{\text{hydrogen gas}}=\frac{0.078}{0.123+0.078}=0.388$

The partial pressure of a gas is given by Raoult's law, which is:

$p_A=p_T\times \chi_A$ ......(2)

where,

$p_A$ = partial pressure of substance A

$p_T$ = total pressure = 663 mmHg

$\chi_A$ = mole fraction of substance A

<u>For nitrogen gas:</u>

$p_{\text{Nitrogen gas}}=663mmHg\times 0.612\\\\p_{\text{Nitrogen gas}}=405.76mmHg$

<u>For hydrogen gas:</u>

$p_{\text{Hydrogen gas}}=663mmHg\times 0.388\\\\p_{\text{Hydrogen gas}}=257.24mmHg$

Hence, the partial pressure of nitrogen gas is 405.76 mmHg and that of hydrogen gas is 257.24 mmHg

4 0

3 years ago

10 The graph below compares the density, in grams per cubic centimeter (g/cm'), of

ahrayia [7]

Answer: the awnser is A

Explanation:

Edge 2020

5 0

3 years ago

Me=9.11×10to the -31 power

weqwewe [10]

True

Explanation:

The mass of an electron is 9.11 x 10⁻³¹kg. It is the lightest subatomic particle compared the protons and neutrons.

Protons weighs 1.67 x 10⁻²⁷kg

Neutrons weighs 1.68 x 10⁻²⁷kg

Electrons carry negative charges.
They were first discovered by J.J Thomson where he called them cathode rays.
They occupy the regions in space around the nucleus.
The regions consists of orbitals and are called sublevels or subshells.

learn more:

Subatomic particles brainly.com/question/2757829

#learnwithBrainly

3 0

3 years ago

Calculate the concentration of acetic acid and acetate ion in a 0.2 M acetate buffer at pH 5. The p K a of acetic acid is 4.76

Levart [38]

Answer:

[Acetic acid] = 0.07 M

[Acetate] = 0.13 M

Explanation:

pH of buffer = 5

pKa of acetic acid = 4.76

$pH=p_{Ka} + log\frac{[Salt]}{[Acid]}$

Now using Henderson-Hasselbalch equation

$5=4.76 + log\frac{[Acetate]}{[Acetic\;acid]}$

$log\frac{[Acetate]}{[Acetic\;acid]} = 0.24$

$\frac{[Acetate]}{[Acetic\;acid]} = 1.74$ ....... (1)

It is given that,

[Acetate] + [Acetic acid] = 0.2 M ....... (2)

Now solving both the above equations

[Acetate] = 1.74[Acetic acid]

Substitute the concentration of acetate ion in equation (2)

1.74[Acetic acid] + [Acetic acid] = 0.2 M

[Acetic acid] = 0.2/2.74 = 0.07 M

[Acetate] = 0.2 - 0.07 = 0.13 M

5 0

3 years ago

Show the empirical formula manganese fluoride; 59.1% Mn and 40.9% F. Fill in the subscripts on the formula below. Make sure to h

Gre4nikov [31]

Hey there!:

Given % of Mn=59.1% means 59.1 g of Mn present in 100 g of manganese fluoride.

Molar mass of Mn= 54.938 g/mol

Moles of Mn = mass / molar mass

59.1 /54.938 => 1.07 ≈ 1 mol.

and % of F=40.9% means 40.9 g of of F present in 100 g of manganese fluoride.

Molar mass of F=18.998 g/mol

Moles of F :

40.9 / 18.999 => 2.15 mol ≈ 2 mol.

The mole ratio between Mn:F= 1 : 2

Therefore the empirical formula of manganese fluoride:

=> MnF2=Mn1F2

Hope that helps!

3 0

4 years ago

Read 2 more answers