Answer:
24g of NaOH are required
Explanation:
Molarity, M, is an unit of concentration widely used in chemistry defined as the ratio between moles of solute (In this case, NaOH), and volume of solution in liters.
We can find the moles of NaOH and its mass with the volume and desired concentration as follows:
<em>Moles NaOH:</em>
400.0mL = 0.400L * (1.50mol / L) = 0.600 moles NaOH
<em>Mass NaOH -Molar mass: 40.0g/mol-:</em>
0.600 moles * (40.0g / mol) =
<h3>24g of NaOH are required</h3>
Answer:
number of dozens = 4.35834 * 10^21 dozens
Explanation:
A dozen contains 12 atoms. To know the number of dozens containing
5.23 * 10^22 atoms, all we have to do is cross multiplication as follows:
1 dozen ...........> 12 atoms
?? dozens ......> <span>5.23 * 10^22
number of dozens = (</span><span>5.23 * 10^22 *1) / (12)
number of dozens = 4.35834 * 10^21 dozens
Hope this helps :)</span>
Answer:
0.5188 M or 0.5188 mol/L
Explanation:
Concentration is calculated as <u>molarity</u>, which is the number of moles per litre.
***Molarity is represented by either "M" or "c" depending on your teacher. I will use "c".
The formula for molarity is:
n = moles (unit mol)
V = volume (unit L)
<u>Find the molar mass (M) of potassium hydroxide.</u>

<u>Calculate the moles of potassium hydroxide.</u>


Carry one insignificant figure (shown in brackets).
<u>Convert the volume of water to litres.</u>


Here, carrying an insignificant figure doesn't change the value.
<u>Calculate the concentration.</u>

<= Keep an insignificant figure for rounding
<= Rounded up
<= You use the unit "M" instead of "mol/L"
The concentration of this standard solution is 0.5188 M.
Answer:
6.70 grams of krypton-81 was present when the ice first formed
Explanation:
Let use the below formula to find the amount of sample

where

here
t = 458,000 years
= 229,000
= \
n =
= 2.000
Now substituting the values



