Answer:
A. Students made a measurement error, because ending with more products is impossible.
Explanation:
The law of conversation of matter tells us that in a chemical reaction, matter is never created or destroyed, it's simply converted from one form to another. So the mass of reactants should always equal the mass of the products in a chemical reaction. If there is excess mass in the product, the students have made an error of some kind.
Answer:
[HCl] = 4.54 M
Explanation:
14.2 % by mass is 14.2 g in 100 g of solution.
Let's calculate the moles of our solute, HCl
14.2 g / 36.45 g/mol = 0.389 mol
Molarity is mol/L (moles of solute in 1L of solution)
Let's determine the volume of solution with density
Solution density = Solution mass / Solution volume
Solution volume = Solution mass / Solution density
Solution volume = 100 g / 1.1684 g/mL → 85.6 mL
For molarity, we need the volume in L. Let's make the unit change.
85.6 mL . 1 L/1000mL = 0.0856L
Molarity is 0.389 mol / 0.0856L → 4.54 M
Answer:
C.Nucleus
Explanation:
The cells are all prokaryotic . This means they do not have a nucleus or any other structures which are surrounded by membranes . ... It is called chromosomal DNA and is not contained within a nucleus.
<h2> part A : </h2><h2>The mass % of KCl =
17.78 %</h2>
<u>calculation </u>
mass%= mass of the solute/mass of the solvent x100
mass of the solute 40 g
mass of the solvent=225
% mass= 40/225 x100=17.78%
<h2>
Part B</h2><h3>The mole fraction of ionic species =0.04296</h3>
the mole fraction=moles of KCl/ moles of the solution
moles of KCl= 40 g/74.5 g/mol=0.537 moles
moles of water = 225g/18 g/mol=12.5 moles
mole fraction is therefore= 0.537/12.5=0.04296