[benworld]

A stoppered bottle, weights 38.215 g when empty , weights 45.362 g when filled with water. When filled with unknown liquid the bottole and unknown weighs 44.221 g. Calculate the liquid's specific gravity :

s.g.. = density of unknown / density of water

Density of water = 1 g/ml

m = 44.221 g - unknown

v = 44.21 - 38.215 = 6.00 ml

d = m /v

d = 44.221 / 6.00 = 7.362 g/ml  unknown

---------------
Fiding density of water

v = 45.362 g - 38.215 g
v = 7.147
d = 45.362 / 7.147 = 6.347 g

------------

Specific Gravity

= 7.362 g/ml 6.347 g/ml  =   1.160 g/ml


is the answer 1.160 g/ml ? Correct or does it make sense ?

Thanks

[stewie griffin]

First off watch your units. For example for density at one point you have it as 6.347 g. Density if g/mL. Similarly in your specific gravity calculation, if you divide g/mL by g/mL then your final quantity should not have units (indeed specific gravity is not supposed to have units).
Let's back up a bit. First you know the density of water is 1 g/mL. So we just need to find the density of the unknown and then we can easily find the specific gravity. Yeah?
To find the density of the unknown we need to know the mass and volume. The mass is easy b/c we know how much the bottle weighs empty and how much it weights when filled with the unknown. So you should be able to find the mass of the unknown (I point this out b/c you are using 44.221g, a MASS, in a VOLUME calculation at one point which isn't right). Good so now we have the mass, time to find the volume.
OH NO! There's no volumes given in the problem. What do we do?? Well we know the density of water, and we also can find out the mass of water it takes to fill the bottle since we are given the empty bottle mass and the bottle filled with water mass. If we know the mass of water, can we find the corresponding volume of water? Sure, use the density to convert from mass to volume. That volume of water will be the same volume that the unknown occupies.
Now we've finally got the mass and volume of the unknown so we find the density. Divide by the density of water to get your specific gravity.

[marquis]

First, a sanity check.  I'm assuming your container is filled to the same level with the water and the unknown.  Your container filled with the unknown weighs less than the same container filled with water.  Assuming the containers are filled to an equal volume, the specific gravity must be less than one. Your value is not.

Next.  Assuming your container is filled to the same level, volume is a constant and cancels out.  Take the weight of the unknown liquid (weight of Bottle filled with unknown - weight of bottle) and divide by the weight of the water (weight of bottle filled with water - weight of bottle).  That's your spec. gravity.

Usually, this test is done on an accurate scale with a pycnometer (basically, a bottle that closely controls volume).  There are many ASTM procedures that go over this method. 

[xoto]

check thru your calculation again