it never will, it will pop
Answer:
B. 0.92 M
Explanation:
Molarity of a solution = number of moles (n) ÷ volume (V)
According to the information provided in this question;
mass of NaCl = 42g
Volume of water = 780mL
Using mole = mass/molar mass
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
mole = 42/58.5
mole (n) = 0.72mol
Volume (V) = 780 mL = 780/1000 = 0.780 L
Hence, molarity = n/V
Molarity = 0.72/0.780
Molarity = 0.923 M
Windblown sand can wear away rock
Given what we know, we can confirm that as with any experiment, the control variable will be the one that through each trial of the experiment, no matter how many times it is performed, stays constant.
<h3>What is a controlled variable?</h3>
- A variable that remains constant through an experiment.
- They are used to compare results to the normal condition.
- They are also used to isolate the changes to one factor at a time and thus know its exact effects on the outcome.
- This increases the accuracy of the data and the subsequent conclusion.
Therefore, we can confirm that if a variable stays constant through each phase and trial of an experiment, it is considered to be a controlled variable and is useful in order to increase the accuracy of the conclusion.
To learn more about control variables visit:
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Answer:
-411 kj
Explanation:
We solve by using this formula
∆U = ∆Q + ∆W
This formula is the first law of thermodynamics
Change in internal energy U = +241
Heat gained by system Q = 652
Putting the value into the equation
+241 = 652 + W
Workdone = 241 - 652
Workdone = -411 kj
Since work done is negative it means that work was done by the system
