. Write a balanced equation for the combustion of propane,
C3H8
When balanced, the equation indicates
that moles of
O2 are required for each mole of C3Hg8

C3H8 + 5O2 = 3CO2 + 4H2O

Explanation:

1.  First start by writing out the unbalanced equation

2.  Count all the atoms on both sides of the equation

C = 3         C =1

H = 8         O=3

O = 2         H =1

3.   Start by balancing the carbon atoms. What would it take to have 3 Carbon atoms on the left? You would add a 3 in front of the carbon atoms on the left side to match the carbon atoms on the right.

4.   Now Try balancing the H atoms. You have 8 H atoms on the right and 1 H atom on the left. To balance these out you would need to add a 4 in front of the H atom which gives you 8 on both sides.

5.  Now balance out the oxygen atoms. Since we added coefficients to the compounds on the left we now have 10 oxygen on the left 4x1=4 + 3x2=6 now balance out the right side of the equation by adding a 5 in front of the O2 5x2 Oxygen gives you 10.

I hope this helps

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.