The balanced chemical equation for the combustion of butane (C4H10) is:

2C4H10 + 13O2 —> 8CO2 + 10H20

Explanation:

When butane undergo Combustion, CO2 and H20 are produced as shown below:

C4H10 + O2 —> CO2 + H20

A clear observation of the above equation proved it is unbalanced. Now let us balance the equation. This is illustrated below:

C4H10 + O2 —> CO2 + H20

There 4 atoms of C on the left side of the equation and 1atom on the right side. It can be balance by putting 4 in front of CO2 as shown below:

C4H10 + O2 —> 4CO2 + H20

There are 10 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 5 in front of H2O as shown below:

C4H10 + O2 —> 4CO2 + 5H20

Now, there are a total of 13 atoms of O on the right side and 2 atoms on the left. It can be balance by putting 13/2 in front of O2 as shown below:

C4H10 + 13/2O2 —> 4CO2 + 5H20

Now multiply through by 2 to clear the fraction

2C4H10 + 13O2 —> 8CO2 + 10H20

Now the equation is balanced.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j