An empty relative density bottle of weight 40g the bottle weight 80g when filled with methylated spirit and 90 when filled with water , what is the relative density of the methylated spirit

Answer 1

The weight of the spirit = (80g + volume of spirit) - 40g
The weight of water = (90g + volume of water) - 80g

Using the formula for relative density:

Relative density of spirit = (weight of spirit / volume of spirit) / (weight of water / volume of water)

We can simplify this by noting that the volume of spirit and water are the same (since they fill the same bottle), so we can cancel them out:

Relative density of spirit = (weight of spirit / weight of water)

Plugging in the given values:

Relative density of spirit = [(80g + volume of spirit) - 40g] / [(90g + volume of water) - 80g]

Relative density of spirit = (40g + volume of spirit) / (10g + volume of water)

Relative density of spirit = (40g + volume of spirit) / (10g + volume of spirit + volume of spirit's weight in water)

To solve for the volume of spirit's weight in water, we can use the fact that the bottle weighs 80g when filled with spirit, and 90g when filled with water:

Volume of spirit's weight in water = (weight of bottle filled with water - weight of bottle filled with spirit) / density of water

Volume of spirit's weight in water = (90g - 80g) / 1g/mL

Volume of spirit's weight in water = 10mL

Plugging this into the previous equation:

Relative density of spirit = (40g + volume of spirit) / (10g + volume of spirit + 10mL)

Simplifying this equation, we get:

Relative density of spirit = (40g + volume of spirit) / (10g + volume of spirit) + 10

Now we can solve for the volume of spirit by using the fact that the bottle weighs 80g when filled with spirit:

Volume of spirit = weight of bottle filled with spirit - weight of empty bottle

Volume of spirit = 80g - 40g

Volume of spirit = 40mL

Plugging this into the previous equation:

Relative density of spirit = (40g + 40mL) / (10g + 40mL) + 10

Relative density of spirit = 1.4

Therefore, the relative density of the methylated spirit is 1.4.