Answer:
B. One or more phase change occur
C. the final state of substance is liquid
D. the sample initially gas
Explanation:
The pressure p = 1.00 atm
The temperature t = 149.2K
The temperature > 119.8K
119.8K being the normal boiling point.
This shows that the krypton is a gas
After it has cooled the pressure = 1.00 atm
The temperature T dropped to 107.8K
T < 115.9K
The melting point has been put as 115.9K
This is a liquid. The final state of the substance is a liquid. Since the temperature is less than the melting point and the pressure is 1.00 atm
Answer:
1.2 ( two significant digits)
Explanation:
5.4 - 4.21 answer should only have the the number of significant digits as the number in the equation with the least number of significant digits... in this case 5.4 is only two significant digits....so the answer should only have two significant digits
5.4 - 4.21 = 1.19 round to two digits = 1.2
Answer:
its mass
its temperature
Explanation:
The heat capacity of a body is the amount of heat needed to raise that temperature of a body by 1k or 1°C.
It is expresses as:
H = m c Ф
where m is the mass of the body
c is the specific heat of the body
Ф is the temperature change of the body
Specific heat capacity is that heat content needed to raise the temperature of a unit mass of a substance by 1k or 1°C
Heat capacity is also known as heat content;
To solve the problem:
since H = m c Ф
we make the unknown c the subject of the expression;
c =
= H / mФ
So to obtain the specific heat capacity, divided the heat capacity by mass and its temperature change.
Answer:
The time required to produce a given quantity of a product is inversely proportional to the rate of the reaction. For a reaction that runs twice as fast, the given quantity of product will be produced in half of the time.
Explanation:
As the reaction progresses to form products, the number of successful collision decreases with increase in time and as rate increases with an increase in the collision between reactants, then time decreases.
With an increase in the system temperature, concentration, surface area and the presence of catalyst, the reaction rate increase alongside decreasing the time needed to turn reactants to products.
For instance, the presence of a catalyst in a reaction speeds up or increases the reaction rate thereby providing an alternative route or pathway to the products thereby decreasing the time of product yield and lowering the activation energy of the reaction.
Therefore as the rate increases, the time needed to convert reactants to products decreases