Answer:
8.55 × 10³ cal
Explanation:
Step 1: Given and required data
- Specific heat of water (c): 1 cal/g.°C
- Initial temperature: 22.7 °C
- Final temperature: 38.8 °C
Step 2: Calculate the temperature change (ΔT)
ΔT = Final temperature - Initial temperature = 38.8 °C - 22.7 °C = 16.1 °C
Step 3: Calculate the heat required (Q)
We will use the following expression.
Q = c × m × ΔT
Q = 1 cal/g.°C × 531 g × 16.1 °C = 8.55 × 10³ cal
Technician A says an ethylene glycol and water mixture lowers the freezing point of the coolant. Technician B says an ethylene glycol and water mixture raises the boiling point of the coolant. Both are correct.
<h3>What is ethylene glycol?</h3>
Ethylene glycol is an organic compound. It is used in two main purposes: manufacture of polyester fiber, and as antifreeze formulation.
It lowers the freezing point of the coolant and raises the boiling point of the coolant.
Thus, Both Technician A and B are correct.
Learn more about ethylene glycol
brainly.com/question/10405060
#SPJ1
Answer:
¹/₁₆
Step-by-step explanation:
The half-life of Pa-234 (6.69 h) is the time it takes for half the Pa to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction
<u>half-lives</u> <u> t/(h) </u> <u>remaining</u>
2 13.38 ¼
3 20.07 ⅛
4 26.76 ¹/₁₆
5 33.45 ¹/₃₂
We see that 26.76 h is four half-lives, and the fraction of Pa-234 remaining
is ¹/₁₆.
<u>Answer:</u> The fraction of the rock that is still composed of potassium-40 is 0.25
<u>Explanation:</u>
To calculate the fraction of the rock that is still composed of K-40, we use the formula:
where,
a = amount of reactant left after n-half lives
= Initial amount of the reactant
n = number of half lives = 2
Putting values in above equation, we get:
Hence, the fraction of the rock that is still composed of potassium-40 is 0.25