Yes it could, but you'd have to set up the process very carefully.
I see two major challenges right away:
1). Displacement of water would not be a wise method, since rock salt
is soluble (dissolves) in water. So as soon as you start lowering it into
your graduated cylinder full of water, its volume would immediately start
to decrease. If you lowered it slowly enough, you might even measure
a volume close to zero, and when you pulled the string back out of the
water, there might be nothing left on the end of it.
So you would have to choose some other fluid besides water ... one in
which rock salt doesn't dissolve. I don't know right now what that could
be. You'd have to shop around and find one.
2). Whatever fluid you did choose, it would also have to be less dense
than rock salt. If it's more dense, then the rock salt just floats in it, and
never goes all the way under. If that happens, then you have a tough
time measuring the total volume of the lump.
So the displacement method could perhaps be used, in principle, but
it would not be easy.
Answer: V = 33.9 L
Explanation: We will use Charles Law to solve for the new volume.
Charles Law is expressed in the following formula. Temperatures must be converted in Kelvin.
V1 / T1 = V2 / T2 then derive for V2
V2 = V1 T2 / T1
= 35 L ( 308 K ) / 318 K
= 33.9 L
Answer
b. 95%
Explanation
Given:
Mass of K₂O produced (actual yield) = 28.56 g
Mass of K that reacted = 25.00 g
Equation: 4K(s) + O₂(g) → 2K₂0(s)
What to find:
The percent yield of K₂O.
Step-by-step solution:
The first step is to calculate the theoretical yield of K₂O produced.
From the balanced equation, 4 mol K produced 2 mol K₂O
Molar mass of K₂O = 94.20 g/mol)
Molar mass of K = 39.10 g/mol)
This means 4 mol x 39.10 g/mol = 156.40 g K produced 2 mol x 94.20 g/mol = 188.40 g K₂O
So 25.00 g K will produce:
Actual yield of K₂O = 28.56 g
Theoretical yield of k₂O = 30.1151 g
The percent yield for the reaction can now be calculated using the formula below:
Therefore, the percent yield for the reaction is 95%.
Answer:
Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A.
Explanation:
