Whoever gets these 2 right gets brainliest! :)

Answer:

B : 0.133 M

Explanation:

moles Li3N3 = 0.4 mol Li x (2 moles Li3N/6 moles Li) = 0.133 M

Answer:

D

Explanation:

because both H's should be positive and O is supposed to be negative.

Answer:

a. pH = 7.0

b. pH = 12.52

c. pH = 12.70

d. pH = 12.78

Explanation:

a. Deionized water has the [H⁺] of pure water = 1x10⁻⁷ (Kw = 1x10⁻¹⁴ = [H⁺][OH⁻] - [H⁺] = [OH⁻ -)

pH = -log[H⁺] = 7

b. Moles NaOH = 5x10⁻³L * (0.10mol / L) = 5x10⁻⁴moles OH⁻ / 0.015L = 0.0333M = [OH⁻]

-Total volume = 10mL+5mL = 15mL = 0.015L

pOH = -log[OH⁻] = 1.48

pH = 14-pOH

pH = 12.52

c. Moles NaOH = 0.010L * (0.10mol / L) = 1x10⁻³moles OH⁻ / 0.020L = 0.0500M = [OH⁻]

-Total volume = 10mL+10mL = 20mL = 0.020L

pOH = -log[OH⁻] = 1.30

pH = 14-pOH

pH = 12.70

d. Moles NaOH = 0.015L * (0.10mol / L) = 1.5x10⁻³moles OH⁻ / 0.025L = 0.060M = [OH⁻]

-Total volume = 10mL+15mL = 25mL = 0.025L

pOH = -log[OH⁻] = 1.22

pH = 14-pOH

pH = 12.78

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 8.12×10²³ atoms are in  90.43 mole of copper.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

number of moles of copper=90.43 moles

Substituting all the given values in the above equation, we get

number of atoms/molecules= 90.43 × 6.022×10²³

number of atoms/molecules=8.12×10²³ molecules

Therefore, 8.12×10²³ atoms are in 90.43 mole of copper.

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Answer:

0.64 L

Explanation:

Step 1: Given data

Step 2: Calculate the volume corresponding to 5.4 kg of oil

Density is an intrinsic property and it is equal to the quotient between the mass and the volume.

ρ = m/V

V = m/ρ

V = 5.4 kg/(8.5 kg/L) = 0.64 L

Answer:

Dipole-dipole interactions

Explanation:

The equilibrium partial pressure of HF is 0.55 atm.

The equation of the reaction is;

        H2(g) + F2(g) ⇄ 2HF

I         2           1             0

C       -x           -x            +x

E     2 - x        1 - x           x

We know that;

pH2 = 2.0 atm

PF2 =  1.0 atm

pHF = ??

Kp = 0.45

So;

Kp = (pHF)^2/pH2. pF2

0.45 = x^2/(2 - x) (1 - x)

0.45 =  x^2/x^2 - 3x + 2

0.45(x^2 - 3x + 2) = x^2

0.45x^2 - 1.35x + 0.9 =  x^2

0.55 x^2 + 1.35x - 0.9 = 0

x = 0.55 atm

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Answer:

32.4 kJ

Explanation:

Given that:

Specific heat capacity fo copper, c = 0.9

Mass of copper, m = 700 g

Temperature change, dθ ;t2 - t1 = (82.1 - 30.7) = 51.4

Energy required, E = mcdθ

E = 700 * 0.9 * 51.4

E = 32382 J

Energy required on kJ

32382 / 1000

= 32.382 kJ

= 32.4 kJ

A severe storm would be most likely to damage a coastal area by causing pollution. Therefore, the correct option is option B.

The region where land joins the ocean, or even as a line defining the border between the land as well as the shoreline, is known as the coast, sometimes referred as the coastline and seashore. The terrain of the area's surroundings has an impact on shorelines, as do water-induced erosion processes like wave action.

The length of the shoreline on Earth is about 620,000 kilometers. Natural ecosystems' coasts are significant zones and frequently the site of a diverse range of biodiversity. They are home to significant ecosystems on land, such as freshwater and estuarine wetlands, that are crucial for the survival of bird populations or other land animals. A severe storm would be most likely to damage a coastal area by causing pollution.

Therefore, the correct option is option B.

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