Answer:
This question is incomplete, here's the complete question:
<em><u>"Suppose 0.0842g of potassium sulfate is dissolved in 50.mL of a 52.0mM aqueous solution of sodium chromate. Calculate the final molarity of potassium cation in the solution. You can assume the volume of the solution doesn't change when the potassium sulfate is dissolved in it. Round your answer to 2 significant digits."</u></em>
Explanation:
Reaction :-
K2SO4 + Na2CrO4 ------> K2CrO4 + Na2SO4
Mass of K2SO4 = 0.0842 g, Molar mass of K2SO4 = 174.26 g/mol
Number of moles of K2SO4 = 0.0842 g / 174.26 g/mol = 0.000483 mol
Concentration of Na2CrO4 = 52.0 mM = 52.0 * 10^-3 M = 0.052 mol/L
Volume of Na2CrO4 solution = 50.0 ml = 50 L / 1000 = 0.05 L
Number of moles of Na2CrO4 = 0.05 L * 0.052 mol/L = 0.0026 mol
Since number of moles of K2SO4 is smaller than number of moles Na2CrO4, so 0.000483 mol of K2SO4 will react with 0.000483 mol of Na2CrO4 will produce 0.000483 mol of K2CrO4.
0.000483 mol of K2CrO4 will dissociate into 2* 0.000483 mol of K^+
Final concentration of potassium cation
= (2*0.000483 mol) / 0.05 L = 0.02 mol/L = 0.02 M
A solution has a pOH of 7. 1 at 10∘c. Then the pH of the solution given that kw=2. 93×10−15 at this temperature is 7.4 .
It is given that,
pOH of solution = 7.1
Kw =2.93×10^(-15)
Firstly, we will calculate the value of pKw
The expression which we used to calculate the pKw is,
pKw=-log [Kw]
Now by putting the value of Kw in this expression,
pKw =−log{2.93×10^(-15)}
pKw =15log(2.93)
pKw=14.5
Now we have to calculate the pH of the solution.
As we know that,
pH+pOH=pKw
Now put all the given values in this formula,
pH+7.1=14.5
pH=7.4
Therefore, we find the value of pH of the solution is, 7.4.
learn more about pH value:
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Sorting the chemical elements in order from least reactive to most reactive, we have:
1. Fluorine (F).
2. Arsenic (As).
3. Antimony (Sb).
4. Silicon (S).
<u>Given the following chemical elements:</u>
Reactivity can be defined as a chemical property which determines how readily a chemical element <u>bonds</u> with other chemical elements, in order to form a new chemical compound.
Generally, the ability of a chemical element to bond with other chemical elements is largely (highly) dependent on the number of valence electrons it has in the outermost shell of its atomic nucleus.
As a general rule, chemical elements that are having <u>fewer</u> number of valence electrons are the most reactive while those having <u>higher</u> valence electrons are least reactive.
Also, chemical reactivity <u>decreases</u> down a group on the periodic table.
Based on the periodic table, the valency for the given chemical elements are:
- <u>Antimony (Sb):</u> 5 valence electrons.
- <u>Silicon (S):</u> 4 valence electrons.
- <u>Fluorine (F):</u> 7 valence electrons.
- <u>Arsenic (As):</u> 5 valence electrons.
In conclusion, sorting the chemical elements in order from least reactive to most reactive, we have:
1. Fluorine (F).
2. Arsenic (As).
3. Antimony (Sb).
4. Silicon (S).
Find more information: brainly.com/question/18214726
Answer is: a possible identity for the unknown compound is C₃H₈.
m(binary compound) = 10.0 g.
m(H₂O) = 16.3 g; mass of water.
M(O₂) = 32 g/mol; molar mass of oxygen.
M(binary compound) = 1.38 · 32 g/mol.
M(binary compound) = 44.16 g/mol.
n(binary compound) = 10 g ÷ 44.16 g/mol.
n(binary compound) = 0.225 mol; amount of substance.
n(H₂O) = 16.3 g ÷ 18 g/mol.
n(H₂O) = 0.9 mol; amount of water.
m(H₂O) : n(binary compound) = 0.9 mol ÷ 0.225 mol.
m(H₂O) : n(binary compound) = 4 : 1.
Unknown cpmpound has 4 times more hydrogen than water, it has 8 hydrogen atoms.
Second element in compound is carbon:
M(X) = 44.16 g/mol - 8 · 1.01 g/mol.
M(X) = 36.08 g/mol ÷ 3.
M(C) = 12.01 g/mol.
