Answer:
0.54g of Cr
Explanation:
Current (I) = 10A
Time (t) = 100s
Molecular mass of Cr = 51.996 amu
Faraday's first law of electrolysis states that
The mass of the substance (m) of a given substance deposited at an electrode is directly proportional to the quantity of electricity or charge (Q) passed
m = nQ
M = mass of the substance
n = electrochemical constant
Q = charge passed through it
Q = IT
Q = (10 * 100) = 1000C
1 moles = molarmass = Faraday's constant (96500C)
Molar mass = Faraday's constant (96500C)
51.996 g = 96500C
How many grams will be liberated with 1000C
51.996g = 96500C
Xg = 1000C
X = (1000 * 51.996) / 96500
X = 51996 / 96500
X = 0.5388g = 0.54 g of Cr will be deposited
<u>Answer:</u> The partial pressure of helium gas is 0.80 atm
<u>Explanation:</u>
Dalton's law of partial pressure states that the total pressure of the system is equal to the sum of partial pressure of each component present in it.
To calculate the partial pressure of helium gas, we use the law given by Dalton, which is:
We are given:
Total pressure of the cylinder, 
= 1.00 atm
Vapor pressure of oxygen gas, 
= 0.20 atm
Putting values in above equation, we get:
Hence, the partial pressure of helium gas is 0.80 atm
You would have started with 5 grams of reactants
Answer:
D. You can no longer tell if your original sample contained Na+ or K+.
Explanation:
Group reagents are the reagents which are used to separate a whole group of cations from the other groups of cations.
For example, for group 1 , the group reagent is HCl and for group 5, the group reagent is ammonium carbonate.
<u>When sodium chloride and potassium carbonate is used, it means we are contaminating our sample with foreign cations which may interfere in the process of detection. Also, we will not be able to decipher whether the sample has these ions in the initial or not as we have added them.</u>
