Answer:
The pressure in mmHg is 1253 (option C)
Explanation:
Two quantities are directly proportional if when multiplying or dividing one of them by a number, the other is multiplied or divided by that number. In other words, the magnitudes are directly proportional when one magnitude increases and so does the other in the same proportion; or when one magnitude decreases and so does the other in the same proportion.
The rule of three or is a way of solving proportionality problems between three known values and an unknown value, which can be applied to directly proportional quantities as follows:
a ⇒ b
c ⇒ x
So 
where a, b and c are data and x is the unknown value to be calculated.
In this case, knowing that 1 Torr = 1 mmHg, the rule of three can be applied as follows: if 1 torr is equal to 1 mmHg, 1253 torr is equal to how many mmHg?

pressure= 1253 mmHg
<u><em>The pressure in mmHg is 1253 (option C)</em></u>
Answer: Molar concentration of the tree sap have to be 0.783 M
Explanation:
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:
where,
= osmotic pressure of the solution = 19.6 atm
i = Van't hoff factor = 1 (for non-electrolytes)
R = Gas constant =
T = temperature of the solution =
Putting values in above equation, we get:


Thus the molar concentration of the tree sap have to be 0.783 M to achieve this pressure on a day when the temperature is 32°C
Answer: single replacement reaction
Explanation:
A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.
A general single displacement reaction can be represented as :

The reaction 
When zinc metal is added to aqueous silver nitrate, zinc being more reactive than silver displaces silver atom from its salt solution and lead to formation of zinc nitrate and silver metal.
The answer is dilute. A dilute salt solution contains a small amount of salt with high water concentration while a concentrated salt solution has a large amount of salt with a lower water concentration. Salt is inorganic hence it is not monounsaturated, which is a term related to organic compounds. The salt is unable to dissolve anymore in a saturated salt solution, leaving the undissolved salt at the bottom and this is not the case here since we only have a small amount of salt.
Circumference of carbon and sulphur is 483.56 & 646.84 respectively