The kelvin temperature of a sample of 678 cm3 ammonia gas is doubled, what is
the new volume?

The new pressure will be

1000 L

, rounded to one significant figure.

Explanation:

Boyle's law states that when a gas is held at a constant temperature and mass in a closed container, the volume and pressure vary inversely. The equation to use is

P

1

V

1

=

P

2

V

2

.

Given

V

1

=

200

mL

×

1

L

1000

mL

=

0.2 L

P

1

=

700 mmHg

V

2

=

100

mL

×

1

L

1000

mL

=

0.1 L

Unknown

P

2

Equation

P

1

V

1

=

P

2

V

2

Solution

Rearrange the equation to isolate

P

2

and solve.

P

2

=

P

1

V

1

V

2

P

2

=

(

700

mmHg

×

0.2

L

)

0.1

L

=

1400 L

, which must be rounded to

1000 L

because all of the measurements have only one significant figure.

Answer link

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).