Answer:
18.018 seconds.
Explanation:
Given that the half life of Manganese, Mn = 3 seconds. The initial sample mass = 90.0 gram, the final sample mass = 1.40 gram.
The general idea to the question is to look for the time it will take to decay from the initial mass that is 90 gram to 1.40 gram.
Therefore, we will be making use of the formula below;
J(t) = J(o) × (1/2)^t/t(hL).
Where t(hL) is the half life, t is the time taken, J(t)= mass after time,t and J(o) is the initial mass. So, let us slot in the values into the equation above.
1.4 = 90 × (1/2)^ t/3.
1.4/90 = (1/2)^t/3.
t/3 = log(0.5) (1.4/90).
+Please note that the 0.5 of the log is at the subscript).
That is the base 0.5 logarithm of (1.4/90) 0.01556 is 6.0060141295.
t = 3 × 6.0060141295.
t = 18.018 seconds.
Answer: The given statement is true.
Explanation:
According to the Dalton's law, total pressure of a mixture of gases that do not react with each other is equal to the partial pressure exerted by each gas.
The relationship is as follows.
or, 
where, 
....... = partial pressure of individual gases present in the mixture
Also, relation between partial pressure and mole fraction is as follows.
where, 
= mole fraction
Thus, we can conclude that the statement Dalton's law of partial pressures states that the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture, is true.
Answer:
Tile 52 and three are incorrect
Explanation:
Answer:
b. mercury
Explanation:
Fishes and some other sea foods are are known to concentrate mercury in their bodies. Consumption of these products gradually accumulate mercury in the body over time.
More specifically, fishes like swordfish, king mackerel and shark are known to concentrate higher amount of mercury than other species of fishes. Hence, limiting their consumption will protect humans from mercury poisoning.
The correct option is b.
KOH+ HNO3--> KNO3+ H2O<span>
From this balanced equation, we know that 1 mol
HNO3= 1 mol KOH (keep in mind this because it will be used later).
We also know that 0.100 M KOH aqueous
solution (soln)= 0.100 mol KOH/ 1 L of KOH soln (this one is based on the
definition of molarity).
First, we should find the mole of KOH:
100.0 mL KOH soln* (1 L KOH soln/
1,000 mL KOH soln)* (0.100 mol KOH/ 1L KOH soln)= 1.00*10^(-2) mol KOH.
Now, let's find the volume of HNO3 soln:
1.00*10^(-2) mol KOH* (1 mol HNO3/ 1 mol KOH)* (1 L HNO3 soln/ 0.500 mol HNO3)* (1,000 mL HNO3 soln/ 1 L HNO3 soln)= 20.0 mL HNO3 soln.
The final answer is </span>(2) 20.0 mL.<span>
Also, this problem can also be done by using
dimensional analysis.
Hope this would help~
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