Hello
This is an example of charles's law equation.
This law established that when the temperature increases, the volume also increases in a proportional relationship.
Let's see the equation:
V1*T2=V2*T1
Where:
V1= initial volume
V2= final volume
T1= Initial temperature
T2=FInal temperature
So, let's suppose that we have an original volume of 2 L and, where the temperature raised by 1°C it expand by twice to 4 L:
Replacing the values of charles's equation as follow:
V1= 2L
V2 =4L
T1 = x (because we don't know the value yet... )
and, as we want to raise the temperature by 1°C:
T2= x +1°C:
Going back to the charles's equation and replacing:
2L*(x+1°C)=4L*x
Then, we have to solve the equation as follow:
2x+2=4x
All terms with x has to be on one side of the equation:
2=4x-2x
2=2x
x=1°C
So the answer is initial temperature= 1°C.
Let's probe this anwer, using charles's law equation with any volume, for example V1= 5L
5L*2°C=V2*1°C
Solving:
V2=5L*2°C/1°C
V2=10L
So for ANY volume value, to expand by twice as much when raised by 1°C the initial temperature has to be 1°C.