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2 years ago

What important points do you need to remember about combustion?

Chemistry

1 answer:

goldenfox [79]2 years ago

7 0

Explanation:

A substance burning in the presence of oxygen and leads to the formation of heat and light is called combustion.

Some important points about combustion are as follows:

Fuel should be present for burning.
Air should be present for the supply of oxygen.
There should be heat (or ignition temperature) to initiate the chemical reaction.

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Oxygen gas can be prepared by heating potassium chlorate according to the following equation:2KClO3(s)Arrow.gif2KCl(s) + 3O2(g)T

Eduardwww [97]

Answer:

Moles of potassium chlorate reacted = 0.2529 moles

The amount of oxygen gas collected will be 12.8675 g

Explanation:

(a)

We are given:

Vapor pressure of water = 17.5 mmHg

Total vapor pressure = 748 mmHg

Vapor pressure of Oxygen gas = Total vapor pressure - Vapor pressure of water = (748 - 17.5) mmHg = 730.5 mmHg

To calculate the amount of Oxygen gas collected, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 730.5 mmHg

V = Volume of the gas = 9.49 L

T = Temperature of the gas = $20^oC=[20+273]K=293K$

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

n = number of moles of oxygen gas = ?

Putting values in above equation, we get:

$730.5mmHg\times 9.49L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 293K\\\\n=\frac{730.5\times 9.49}{62.3637\times 293}=0.3794mol$

According to the reaction shown below as:-

$2KClO_3(s)\rightarrow 2KCl(s) +3O_2(g)$

3 moles of oxygen gas are produced when 2 moles of potassium chlorate undergoes reaction.

So,

0.3794 mol of oxygen gas are produced when $\frac{2}{3}\times 0.3794$ moles of potassium chlorate undergoes reaction.

Moles of potassium chlorate reacted = 0.2529 moles

(b)

We are given:

Vapor pressure of water = 17.5 mmHg

Total vapor pressure = 753 mmHg

Vapor pressure of Oxygen gas = Total vapor pressure - Vapor pressure of water = (753 - 17.5) mmHg = 735.5 mmHg

To calculate the amount of Oxygen gas collected, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 735.5 mmHg

V = Volume of the gas = 9.99 L

T = Temperature of the gas = $20^oC=[20+273]K=293K$

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

n = number of moles of oxygen gas = ?

Putting values in above equation, we get:

$735.5mmHg\times 9.99L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 293K\\\\n=\frac{735.5\times 9.99}{62.3637\times 293}=0.40211mol$

Moles of Oxygen gas = 0.40211 moles

Molar mass of Oxygen gas = 32 g/mol

Putting values in above equation, we get:

$0.037mol=\frac{\text{Mass of Oxygen gas}}{2g/mol}\\\\\text{Mass of Oxygen gas}=(0.40211mol\times 32g/mol)=12.8675g$

Hence, the amount of oxygen gas collected will be 12.8675 g

5 0

2 years ago

The process of_ causes rock to change compostion when reacting with oxgen

satela [25.4K]

Rusting causes rocks with metals in them to corrode and have changed compositions. The oxygen in the moisture in the air causes rock to rust.

3 0

2 years ago

Read 2 more answers

A solute is a strong electrolyte that ionizes into 2 ions. What is the molar mass of this solute if 30.76 grams added to exactly

Whitepunk [10]

Answer:

34.9 g/mol is the molar mass for this solute

Explanation:

Formula for boiling point elevation: ΔT = Kb . m . i

ΔT = Temperatures 's difference between pure solvent and solution → 0.899°C

Kb = Ebullioscopic constant → 0.511°C/m

m = molality (moles of solute/1kg of solvent)

i = 2 → The solute is a strong electrolyte that ionizes into 2 ions

For example: AB ⇒ A⁺ + B⁻

Let's replace → 0.899°C = 0.511 °C/m . m . 2

0.899°C / 0.511 m/°C . 2 = m → 0.879 molal

This moles corresponds to 1 kg of solvent. Let's determine the molar mass

Molar mass (g/mol) → 30.76 g / 0.879 mol = 34.9 g/mol

4 0

2 years ago

What happens when The vapour obtained by dropping conc. H2SO4 in a mixture of KI and MnO2 is treated with hypo solution

Shalnov [3]

Iodine is decolorized.

The first reaction stated in the question occurs as follows;

2 KI (aq) + 2 H2SO4 (aq) + MnO2 (s) → MnSO4 (aq) + K2SO4 (aq) + I2 (s) + 2 H2O (l)

The reaction here is the formation of iodine from MnO2 and KI in the presence of dropwise H2SO4.

Hypo is the common name of sodium thio-sulphate or sodium hypo-sulfite.

The equation of the titration reaction is;

2Na2S2O3 + I2→ Na2S4O6 + 2NaI

When this reaction takes place, iodine is decolorized due to its reduction to I^-.

6 0

2 years ago

Write the condensed nd structural formulas as well as the names for all isomers of C3H5Cl3.

Sergio039 [100]

Answer:

1) 1,1,1-trichloropropane

2) 1,1,2-trichloropropane

3) 1,2,2-trichloropropane

4) 1,2,3-trichloropropane

Explanation:

For this question, we must remember that isomers are molecules that have the same formula but different structures. For the formula $C_3H_5Cl_3$ we can draw a linear chain of three carbons and change the position of the chlorine atoms in the carbon chain.

With this in mind, if we put all the chlorine atoms on the same carbon we will get 1,1,1-trichloropropane. If we change an atom from chlorine to carbon 2 we will obtain 1,1,2-trichloropropane. If we move another chlorine atom to carbon two we will get 1,2,2-trichloropropane. Finally, if we put a chlorine atom in each carbon we will obtain 1,2,3-trichloropropane.

See figure one for further explanations

I hope it helps!

4 0

3 years ago