Answer:
Molecular formula = C20H30
Explanation:
NB 440mg = 0.44g, 135mg= 0.135g
From the question, moles of CO2= 0.44/44= 0.01mol
Since 1 mol of CO2 contains 1mol of C, it implies mol of C = 0.01
Also from the question, moles of H2O = 0.135/18= 0.0075mole
Since 1 mol of H2O contains 2mol of H, it implies mol of H = 0.0075×2= 0.015 mol of H
To get the empirical formula, divide by smallest number of mole
Mol of C = 0.01/0.01=1
Mol of H = 0.015/0.01= 1.5
Multiply both by 2 to obtain a whole number
Mol of C =1×2 = 2
Mol of H= 1.5×2 = 3
Empirical formula= C2H3
[C2H3] not = 270
[ (2×12) + 3]n = 270
27n = 270
n=10
Molecular formula= [C2H3]10= C20H30
Answer:
Base on the properties the substances possess the substance change phase from gas to liquid.
Explanation:
Generally, matter can exist in three phase namely liquid , solid and gas. The scientist has a container with a substance inside.
At first the substance moves away from each other . This means the substance was first in the gas phase . Gas molecules, because of the energy they possess , it can move rapidly and randomly and most at times move away from each other . The gas molecules tends to fill the whole volume of the container and the shape of gases are indefinite.
Later the molecules move around each other. This is a property of a liquid . A substance in liquid phase have the ability to move freely but they stay together because of the force of attraction holding them together . The substance only have the ability to move around each other because the forces holding them together won't allow them to move apart.
Base on the properties the substances possess the substance change phase from gas to liquid.
<u><em>on the basis of the reaction of heat in plastic , their are two types of plastics : </em></u>
<h2><u>
<em>Thermoplastic & Thermosetting plastics </em></u></h2>
<u><em>Thermoplastics : Plastics which easily get deformed (become soft )on heating and also get bend easily are known as thermoplastics . </em></u>
<u><em>examples : polythene , polyvinyl chloride and polystyrene .</em></u>
<u><em>thermosetting plastics : plastics which once moulded into a shape do not become soft on heating and cannot be moulded again are called thermosetting plastics .</em></u>
<u><em>examples : bakelite , melamine and formica</em></u>
Answer:
C. 2.70 g/mL
Explanation:
Density is the ratio between the mass of a substance and the volume it occupies. Based on Archimedes' volume, the displaced volume of the aluminium is the volume it occupies. To solve this question we must find the difference in volume between initial volume of water = 30mL and final volume of water + aluminium = 39.26mL. This difference is the volume of the aluminium. With its mass we can find density:
39.26mL - 30mL = 9.26mL
Density = 25.00g / 9.26mL =
2.70g/mL
Right answer is:
<h3>C. 2.70 g/mL
</h3>
