Use the volume and density of the gold statue to calculate the mass of the statue.
density = mass / volume, or rearranged, mass = density • volume
Convert the volume of the statue from L to mL so volume unit agrees with density unit
mass of statue = 19.3 g/mL • 1000 mL = 19 300 g
Mass of sand must be same as the mass of the statue, 19 300 g
Use the mass and density of the sand to calculate the volume of sand needed
density = mass / volume, or rearranged, volume = mass / density
volume of sand needed = 19 300 g / 23 g/mL = 8391 mL or 8.391 L
1b
Calculate the density of the statue from the measured mass and volume. If the calculated density agrees with the known density of gold, then the statue is made from pure gold.
density = mass / volume
Convert the mass from kg to g as you want the answer in g/mL so you can compare it to the reference value of gold given in the problem. 16.5 kg • 1000 g / 1 kg = 16 500 g
density of the statue = 16 500 g / 954 mL = 17.3 g/mL
Since this density, 17.3 g/mL is significantly different from the known density of gold, 19.3 g/mL, the statue cannot be made of pure gold. The gold was mixed with a less dense metal.
We know the volume of one mole of gas at 273 K and 760 Torr is 22.4 L. Using
(PV)/T = constant
We can calculate the volume of the gasses at the given conditions:
(P₁V₁)/T₁ = (P₂V₂)/T₂
(760 * 22.4) / 273 = (288 V₂) / 308.2
V₂ = 66.7 L
Mass of He: 4
Mass of Ne: 20
Fraction of Ne: x
Fraction of He: 1 - x
avg density = (∑(component fraction × component mass))/volume
0.2460 = (20x + 4(1 - x))/ 66.7
x = 0.775
One characteristic of a lagoon is often: concentrated salt.
The screen will not be useful in separating the mixture of saw dust, salt and pebbles.
Answer: Option C
<u>Explanation:
</u>
The separation of individual elements from the mixture can be done easily if the size of the elements in the mixture is varying significantly. Just like in the present case, the size of sawdust and salt is very small compared to that of pebbles.
So by using sieves having pores of smaller sizes, pebbles can be separated from the mixture as pebbles will not pass through the minute pores. Even depending upon the size of pores, the saw dust can also be separated using it.
Similarly, we can use water also to separate this mixture as sawdust have least density it will float in water surface and pebbles being the highest density will sink and settle in the bottom of the container.
Remaining salt will get dissolved in water which can be obtained by heating the water in order to precipitate the salt. Even filter paper with different mess size will also help in separating this mixture. But as this mixture is not permeable through screen, the screen cannot be used to separate this mixture.
