Is this a test or something else?
A molecular formula represents the exact number of atoms present for each element in the compound.
For carbon atom: 
= 
( as molar mass of carbon is 12 g/mol)
Now, 6 carbon atoms are present and rest are hydrogen atoms i.e. 6
Thus, formula becomes 
( 
Now, check for unsaturation:
Degree of unsaturation = 
Substitute the value of x and y,
Degree of unsaturation = 
= 
= 
implies one ring and three double bonds.
Thus, formula comes out to be i.e. benzene ring.
B.
Isotopes is an atom has same number of electrons and protons but different number of neutron.
Answer: 150N
Explanation:
The formula to calculate the force will be the mass multiplied by the acceleration. In this case, mass = 15kg and acceleration = 10m/s². Therefore, force will be:
= Mass × Acceleration
= 15 × 10
= 150N
The force is 150Newton
Part 1 : Answer is only B substance is soluble in water.
In this experiment undissolved mass of each substance was measured. According to the given data, undissolved mass of substance B at 20 °C is 10 g while A is 50 g. Since, the initial added mass of each substance is 50 g, we can see that substance A is not soluble in water since the undissolved mass is 50 g.
Part 2 : Substance A is not soluble in water and substance B is soluble in water.
According to the given data, the undissolved mass of substance A remains as same as initial added mass, 50 g throughout the temperature range from 20 ° to 80 °C. Hence, we can conclude that substance A is not soluble in water.
But, according to the data, undissolved mass of substance B at 20 °C is 10 g. That means, 40 g of substance B was dissolved in water. When the temperature increases the undissolved mass of substance B decreases. Hence, we can conclude that substance B is soluble in water and solubility increases with temperature.
