Answer:
Since with LiBr no precipitation takes place. So, Ag+ is absent
When we add Li2SO4 to it, precipitation takes place.
Ca2+(aq) + SO42-(aq) ----> CaSO4(s) ...Precipitate
Thus, Ca2+ is present.
When Li3PO4 is added, again precipitation takes place.Reaction is:
Co2+(aq) + PO43-(aq)---->Co3(PO4)2(s) ... Precipitate
A. Ca2+ and Co2+ are present in solution
B. Ca2+(aq) + SO42-(aq) ----> CaSO4(s)
C. 3Co2+(aq) + 2PO43-(aq)---->Co3(PO4)2(s)
Mass is measured against a standard by using a balance. The statement given above is a fact. Therefore the answer among the choices is letter "A" or "A. True". I hope this helps you on your assignment.
I think it is "Known".
Radioactive decay is measured using a formula where the half-life <span>of an isotope is the time it takes for the original nuclei to decay half of its original amount.</span>
Answer:
The volume of the second cylinder is 80 liters
Explanation:
We use the Boyle-Mariotte formula, according to which the pressure and volume of a gas are inversely related, keeping the temperature constant: P1 x V1 = P2xV2. We convert the pressure in mmHg to atm:
760 mmHg-----1 atm
380mmHg------x= (380mmHgx1atm)/760mmHg=0,5 atm
P1xV1=P2xV2
2 atmx20 L= 0,5atm x V2 V2=(2 atmx20 L)/0,5atm=80L
Scientists should control most possible variables in experiments to get the most valid and correct data. If many variables are included in experiments it is more difficult to interpret what is causing a different outcome.