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3 years ago

Hello rainfaeries ~help me with these questions

Chemistry

2 answers:

zimovet [89]3 years ago

7 0

Answer:

Ans) Calcium hydroxide is produced by the reaction of water and calcium oxide also called slaked lime.

CaO + H2O → Ca(OH)

Ans) When Calcium Hydroxide reacts with water (H2O) and absorbs carbon dioxide (CO2) from the environment, it produces Calcium Carbonate (CaCO3), which creates a hard coating on the walls. That's why Calcium Hydroxide is used in white washing.

goblinko [34]3 years ago

4 0

Explanation:

Calcium hydroxide is produced commercially by treating lime with water: CaO + H2O → Ca(OH) In the laboratory it can be prepared by mixing aqueous solutions of calcium chloride and sodium hydroxide.

Quicklime is used for whitewashing as it produces calcium hydroxide (CaOH) when it reacts with water (H2O) and absorbs carbon dioxide (CO2) from the environment, as a result, it produces calcium carbonate (CaCO3) which creates a hard coating on the walls.

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Nitrogen effuses through a pinhole 1.7 times as fast as another gaseous element under the same conditions. Estimate the other el

marysya [2.9K]

Answer:

80.92, Krypton

Explanation:

<u>What is effusion?</u>

• It is a process where gas escapes through a pinhole (a very small hole) into a region of low pressure or vacuum

<u>Graham's law of effusion of </u><u>gas</u>

• states that at a given constant temperature and pressure, the rate of effusion of gases is inversely proportional to the square root of their molar masses

$\boxed{ \frac{Rate_1}{Rate_2} = \sqrt{ \frac{M_2}{M_1} } }$

<u>Calculations</u>

Nitrogen exist as N₂ at room temperature, thus its molar mass is 2(14)= 28.

Let the rate and molar mass of unknown gas be Rate₂ and M₂ respectively.

Since N₂ effuses 1.7 times as fast as the unknown gas,

Rate₁= 1.7(Rate₂)

$\frac{Rate_1}{Rate_2} = 1.7$

$1. 7 = \sqrt{ \frac{M_2}{28} }$

Square both sides:

$2.89 = \frac{M_2}{28}$

Multiply both sides by 28:

2.89(28)= M₂

M₂= 80.92

<u>Identity of </u><u>gas</u>

The molar mass of 80.92 lies between Bromine and Krypton. However since Bromine exist as Br₂, the value of it's molar mass would be 159.8 instead. Hence, Bromine is eliminated.

If the gas is a diatomic element, the atomic weight is 80.92 ÷2= 40.46. Thus, we are now considering if Argon could be its identity. However, Argon is a noble gas and will not exist as a diatomic element. Argon is therefore eliminated too.

Thus based on the above reasoning, its probable identity is Krypton.

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3 years ago

Silver is produced as a byproduct of gold

VashaNatasha [74]

Answer:

Element Properties

atomic number 47

atomic weight 107.868

melting point 960.8 °C (1,861.4 °F)

boiling point 2,212 °C (4,014 °F)

specific gravity 10.5 (20 °C [68 °F])

oxidation states +1, +2, +3

electron configuration [Kr]4d105s1

hope that helps

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3 years ago

4Al(s) + 3O2(g) 2Al2O3 (s) How many molecules of O2 are used in the reaction?

lutik1710 [3]

3 molecules of O2 are used in this reaction.

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4 years ago

Which part of a food chain absorbs the Sun's light and heat

ExtremeBDS [4]

Answer:

I think it's plants.

Explanation:

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3 years ago

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A mining company is interested in monazite, a mineral substance that forms in igneous rock in Earth’s interior. They think they

VARVARA [1.3K]

Sedimentary rock can be minazute by adding more heat n pressure

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3 years ago

Hello rainfaeries ~help me with these questions ​

Hello rainfaeries ~help me with these questions