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2 years ago

How many grams of Ca(OH)2are required to make 1.5 L of a 0.81 M solution?

Chemistry

1 answer:

FrozenT [24]2 years ago

5 0

Answer:

Mass = 90.28 g

Explanation:

Given data:

Mass of Ca(OH)₂ = ?

Volume of solution= 1.5 L

Molarity of solution = 0.81 M

Solution:

First of all we will calculate number of moles.

Molarity = number of moles / volume in L

by putting values,

0.81 M = Number of moles / 1.5 L

Number of moles = 0.81 M × 1.5 L

Number of moles = 1.22 mol

Mass of Ca(OH)₂ in gram:

Mass = number of moles × molar mass

Mass = 1.22 mol × 74.09 g/mol

Mass = 90.28 g

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1) 16.8 L CO2

2) 36.96 L NH3

3) 9.88 L CO2

4) 56.99 L H2O

Explanation:

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2. Hydrogen gas reacts with 23.1 g of nitrogen gas to produce ammonia (NH3). What volume of ammonia will be produced at STP?

3H2 + N2 → 2NH3

Moles N2 = 23.1 grams / 28.0 g/mol

Moles N2 = 0.825 moles

For 3 moles H2 we need 1 mol N2 to produce 2 moles NH3

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3. Iron (III) oxide reacts with carbon monoxide to form iron and carbon dioxide. How many liters of carbon dioxide will be produced from 23.5 g of iron (III) oxide when at STP?

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3 years ago

A microwave can have a frequency of 3.8 X 1010Hz. How much energy does this microwave give off in joules?

Marina86 [1]

Answer:

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The energy given off by the microwave can be determined by the application of Planck's energy formula:

E = hf

where: E is the required energy, h is Planck's constant (6.626 x $10^{-34}$ $m^{2}$ Kg/s), and f is the frequency (3.8 x $10^{10}$ Hz).

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