1. 1
2. 2
3. 2
4. 1
i am pretty sure
B. The unknown solution had the lower concentration.
Explanation:
Osmosis is a phenomenon in which the molecules of the solvent has a tendency to move through a membrane which is semipermeable from lower concentrated side to the higher concentration side, so that the concentrations on both sides of the membrane must be equal.
So the unknown solution may have lesser concentration than the isotonic solution so that molecules of that solution move from less concentrated side to the more concentrated side, so its level drops.
At s.t.p, the volume of a gas =22.4dm³
Talking the problem,
At 1atm, 273K the volume =7 moles *22.4dm³/mol
At 323K, 2.90atm, volume =?
The combined gas equation
P1v1/T1=P2v2/T2
P1=1atm
P2=2.9atm
T1=273K
T2=323K
V1=156.8dm³
Therefore,
1*156.8dm³/273=2.9atm*V2/323
V2=(156.8dm³*323K)/(273K*2.9atm)
= 64dm³
When it begins to have a chemical affect
Answer:
1. Physical Weathering
2. Option B
Explanation:
1. Physical weathering
On Mars, there are two types of weathering agents a) wind and b) acid fog. Thus, they will carry out only physical weathering
2. Option B
3D can be used to produce things that are required on the Mars and also the locally available raw material can be used for printing thereby saving the cost.