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3 years ago

Why burning of fuel is a chemical change give 5 reasons to support your answer

Chemistry

1 answer:

frozen [14]3 years ago

6 0

Answer:

Explanation:

1. New substances such as carbondioxide and water is formed.

2. There is evolution of gas bubbles. Gases are released.

3. There is either the absorption of energy or release of energy in form of light and energy.

4. The reaction is irreversible i.e it cannot be reversed, it is permanent once the reaction take place.

5. There is a change in both odor and smell.

A chemical change is a change where new substances are formed due to changes in the properties.

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Is hydrogen a solid liquid or gas?

Anestetic [448]

It can be in either state.....

8 0

3 years ago

Water electrolysis of hcl ? Please

svp [43]

Answer:

Electrolysis (of hydrochloric acid) is a way of splitting up (decomposition) of the compound (hydrogen chloride in water) using electrical energy.

Explanation:

The electrical energy comes from a d.c. (direct current) battery or power pack supply. A conducting liquid, containing ions, called the electrolyte (hydrochloric acid), must contain the compound (hydrogen chloride) that is being broken down.

4 0

3 years ago

Write the molecular formula for a compound with the possible elements C, H, N and O that exhibits a molecular ion at M

liberstina [14]

Answer:

$= \mathbf{C_3H_6O}$

Explanation:

From the given information, since the molecular mass of the ion M+ is not given;

Let's assume M+ = 58.0423

So, by applying the 13th rule;

we will need to divide the mass by 13, after dividing it;

The quotient n = no. of carbon; &

The addition of the quotient (n) with the remainder r = no. of hydrogen.

So;

$\dfrac{58}{13}= 4 \ remainder \ 6$

So;

$C_nH_{n+r} = C_4H_{4+6}$

$= C_4H_{10}$

From the given information; we have oxygen present, so since the mass of oxygen = 16, we put oxygen in the molecular formula by removing $CH_4$ . Also, since the mass is an even number then Nitrogen is 0.

So, we have:

$= \mathbf{C_3H_6O}$

6 0

2 years ago

In a first-order decomposition reaction, 50.0% of a compound decomposes in 10.5 min.

mihalych1998 [28]

In this reaction 50% of the compound decompose in 10.5 min thus, it is half life of the reaction and denoted by symbol $t_{1/2}$ .

(a) For first order reaction, rate constant and half life time are related to each other as follows:

$k=\frac{0.6932}{t_{1/2}}=\frac{0.6932}{10.5 min}=0.066 min^{-1}$

Thus, rate constant of the reaction is $0.066 min^{-1}$ .

(b) Rate equation for first order reaction is as follows:

$k=\frac{2.303}{t_{1/2}}log\frac{[A_{0}]}{[A_{t}]}$

now, 75% of the compound is decomposed, if initial concentration $[A_{0} ]$ is 100 then concentration at time t $[A_{t} ]$ will be 100-75=25.

Putting the values,

$0.066 min^{-1}=\frac{2.303}{t}log\frac{100}{25}=\frac{2.303}{t}(0.6020)$

On rearranging,

$t=\frac{2.303\times 0.6020}{0.066 min^{-1}}=21 min$

Thus, time required for 75% decomposition is 21 min.

8 0

3 years ago

The mass of a radioactive substance follows a continuous exponential decay model, with a decay rate parameter of 8.1% per day. f

Elanso [62]

The general equation for radioactive decay is;
N = N₀e^(-λt)
x - decay constant (λ) - rate of decay
t- time
N - amount remaining after t days , since we are calculating the half life, amount of time it takes for the substance to to be half its original value, its N₀/2
N₀ - amount initially present
substituting the values
N₀/2 = N₀e^(-0.081t)
0.5 = e^(-0.081t)
ln (0.5) = -0.081t
-0.693 = -0.081t
t = 0.693 / 0.081
= 8.55
half life of substance is 8.55 days

5 0

3 years ago