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2 years ago

7. Calculate the amount of sodium hydroxide you will need to make 250 mL of a 0.1 M solution of sodium hydroxide.

Chemistry

1 answer:

tresset_1 [31]2 years ago

7 0

Answer:

1 g

Explanation:

Given data:

Volume of solution = 250 mL (250 mL × 1 L/1000 mL = 0.25 L)

Molarity of solution = 0.1 M

Amount of sodium hydroxide = ?

Solution:

Molarity = number of moles / volume in L

0.1 M = number of moles /0.25 L

Number of moles = 0.1 M × 0.25 L

M = mol/ L

Number of moles = 0.025 mol

Mass of sodium hydroxide:

Mass = number of moles × molar mass

Mass = 0.025 mol ×40 g/mol

Mass = 1 g

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2 years ago

Read 2 more answers

Acetylene (C2H2), an important fuel in welding, is produced in the laboratory when calcium carbide (CaC2) reacts with water: CaC

Anastaziya [24]

Answer:

There are 1.287 grams of acetylene collected

Explanation:

Total gas pressure = 909 mmHg

Vapor pressure of water = 20.7 mmHg

Pressure of acetylene = 909 mmHg - 20.7 mmHg = 888.3 mmHg

1mmHg = 1 torr

22 ° C + 273.15 = 295.15 Kelvin

Ideal gas law ⇒ pV = nRT

⇒ with p = pressure of the gas in atm

⇒ with V = volume of the gas in L

⇒ with n = amount of substance of gas ( in moles)

⇒ with R = gas constant, equal to the product of the Boltzmann constant and the Avogadro constant (62.36 L * Torr *K^−1 *mol^−1)

⇒ with T = absolute temperature of the gas (in Kelvin)

888.3 torr * 1.024 L = n * 62.36 L * Torr *K^−1 *mol^−1 * 295.15 K

n = 0.04942 moles of C2H2

Mass of C2H2 = 0.04942 moles x 26.04 g/mole = 1.287 g

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2 years ago

A chemist carefully measures the amount of heat needed to raise the temperature of a 894.0g sample of a pure substance from to −

astraxan [27]

Answer:

C = 0.2349 J/ (g °C)

Explanation:

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C = H / mΔT

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2 years ago