Empirical formula is the simplest ratio of components making up a compound.
The percentage composition of each element has been given
therefore the mass present of each element in 100 g of compound is
B N H
mass 40.28 g 52.20 g 7.53 g
number of moles
40.28 g / 11 g/mol 52.20 g / 14 g/mol 7.53 g / 1 g/mol
= 3.662 mol = 3.729 mol = 7.53 mol
divide the number of moles by the least number of moles, that is 3.662
3.662 / 3.662 3.729 / 3.662 7.53 / 3.662
= 1.000 = 1.018 = 2.056
the ratio of the elements after rounding off to the nearest whole number is
B : N : H = 1 : 1 : 2
therefore empirical formula for the compound is B₁N₁H₂
that can be written as BNH₂
The correct answer is option B. Dirty water is a mixture of solid particles and liquid. It is both a mixture and pure substance.
The dirty water sample has both gravel and liquid water in it. After filtration the gravel is removed so the water sample looks clearer than before filtration. Liquid water is a pure substance because it is a compound that is made up of elements hydrogen and oxygen. Now the gravel is only physically combined with the liquid water, thus giving the water sample properties of a mixture. And like any mixture, gravel is physically separated through filtration from the liquid water.
Thus the water sample of the chemists is both a mixture and pure substance.
Answer:
A. It would float with about 80% of the cube below the surface of the water and 20% above the surface.
Explanation:
The choice that best describes what happens to cube of the given density value is that it would float with about 80% of the cube would be below the surface of the water and 20% above the surface.
Density is the mass per unit volume of a substance. The more mass a body has relative to volume, the great it's density. In short, density is directly proportional to mass and inversely related to volume.
The density of water is 1g/mL
If the density of the cube were to be the same with that of water, the substance will just mix up with water .
Here the density is less than that of water.
The density is 0.2g/mL
Therefore, 20% will stay afloat and 80% will be below the surface of the water.
The answer is d, hand soap.
Hand soap is alkaline and red litmus paper turns blue when exposed to alkaline solution.
Answer: Option (D)
Explanation: Chemical weathering refers to the breakdown of minerals and forming new minerals due to the presence of chemical elements. For example, hydrolysis.
Due to the chemical weathering, initially, the minerals will get dissolved and are carried to the streams and oceans. After that, due to the saturation by water, the crystals will be precipitated out of that existing solution.
This crystals then sinks down to the bottom, forming sedimentary rocks.
Thus, the correct answer is option (D).
