All categories

3 years ago

What important points do you need to remember about combustion?

Chemistry

1 answer:

goldenfox [79]3 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.

You might be interested in

Calculate the reaction quotient Qp for the following redox reaction: 14H+ + Cr2O72- + 6Cl- ----> 2Cr3+ + 3Cl2 + 7H2O The reac

stich3 [128]

Answer:

Value of $Q_{p}$ for the given redox reaction is $1.0\times 10^{-8}$

Explanation:

Redox reaction with states of species:

$14H^{+}(aq.)+Cr_{2}O_{7}^{2-}(aq.)+6Cl^{-}(aq.)\rightarrow 2Cr^{3+}(aq.)+3Cl_{2}(g)+7H_{2}O(l)$

Reaction quotient for this redox reaction:

$Q_{p}=\frac{[Cr^{3+}]^{2}.P_{Cl_{2}}^{3}}{[H^{+}]^{14}.[Cr_{2}O_{7}^{2-}].[Cl^{-}]^{6}}$

Species inside third braket represent concentration in molarity, P represent pressure in atm and concentration of $H_{2}O$ is taken as 1 due to the fact that $H_{2}O$ is a pure liquid.

$pH=-log[H^{+}]$

So, $[H^{+}]=10^{-pH}$

Plug in all the given values in the equation of $Q_{p}$ :

$Q_{p}=\frac{(0.10)^{2}\times (0.010)^{3}}{(10^{-0.0})^{14}\times (1.0)\times (1.0)^{6}}=1.0\times 10^{-8}$

7 0

3 years ago

If a chemical reaction occurs in a direction that has a positive change in entropy thenGroup of answer choicesthe change in enth

mezya [45]

Answer:

The reaction must be spontaneous, the disorder of the system increases.

Explanation:

By the Second Law of Thermodynamics, a positive change in entropy is due to a net input heat, and entropy is a measure of the grade of disorder within the system. The net input heat means that resultant goes to the system from the surroundings.

By the First Law of Thermodynamics, a net input heat is due to a positive change in enthalpy.

The reaction is endothermic and spontaneous (since change in entropy is positive).

6 0

3 years ago

A classroom has a volume of 278 m3. What is its volume in<br> km3

Tcecarenko [31]

1 m = 0,001 km
1m³ = 0,000000001 km³

278 m³ = 0,000000278 km³ = 2,78×10^(-7) km³

:•)

3 0

3 years ago

Read 2 more answers

Dinitrogen tetraoxide, a colorless gas, exists in equilibrium with nitrogen dioxide, a reddish brown gas.

viktelen [127]

Explanation:

N2O4(g) <----------> 2NO2(g)

Before proceeding,

A chemical equilibrium can be defined as a condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs.

Statement 1.

This statement is false. Equilibrium is not about equal concentrations but rather zero change in concentration of the reactants and products.

Statement 2.

This statement is True in chemical equilibrium; the forward and reverse reactions occur at equal rates.

Statement 3.

This statement is False. The rate constant for the forward reaction is not equal to the rate constant of the reverse reaction.

Statement 4.

The concentration of NO2 divided by the concentration of N2O4 is NOT equal to a constant. To obtain a constant value irregardless of the concentrations, the concentration of NO2 must be squared. This comes from the stoichiometry of the reaction

Kc= [NO2]2 / [N2O4]

This statement is false.

3 0

3 years ago

19. Which of the following chemical equations represents

Lesechka [4]

Answer:

C₃H₈ (g) + 5O₂(g) → 3CO₂ (g) + 4H₂O (l)

(option D. with the proviso that the subscripts of propane's chemical formula must be corrected)

Explanation:

<em>Propane</em> is the saturated hydrocarbon, alkane, with chemical formula C₃H₈ or CH₃CH₂CH₃.

The complete combustion of the hydrocarbons yield carbon dioxide (CO₂) and water (H₂O).

The chemical equation that represents this combustion is:

C₃H₈ (g) + O₂(g) → CO₂ (g) + H₂O (l) (skeleton equation: unbalanced)

Once you balance it, you get:

C₃H₈ (g) + 5O₂(g) → 3CO₂ (g) + 4H₂O (l)

Left side Right side

C 3 3

H 8 4×2 = 8

O 5×2 = 10 3×2 + 4 = 10

That equation corresponds to the option D. of the list, with the proviso that the subscripts of propane's chemical formula must be corrected

6 0

3 years ago