○ c. ○
◘
because a Research bias, also called experimenter bias, is a process where the scientists performing the research influence the results, in order to portray a certain outcome.
◘
hope that helped ♥
Answer:
- What distinguish a solution in general from an aqueous solution is the solvent. A solution in general may contain any solvent, which may be solid, liquid or gas, while an aqueous solution is formed with water as solvent.
Explanation:
A solution in general is a homogeneous mixture in which a substance, named solute, is dissolved, in other substance, name solvent.
Solutions may be in solid, liquid or gas state. There are many kind of solvents. Usually, in a lab you work with liquid solutions. Some liquid solvents are: ethanol, glycerin, hexane, benzene, and water, among many others.
Aqueous solution is a solution where the solvent is water. Of course, the solute may be any one: NaCl, sugar, ethanol, an acid, a base, a salt.
What distinguish a solution in general and an aqueous solution is the solvent.
Rusting causes rocks with metals in them to corrode and have changed compositions. The oxygen in the moisture in the air causes rock to rust.
Answer:
The answer to your question is below
Explanation:
Data
mass of CaCO₃ = 155 g
mass of HCl = 250 g
mass of CaCl₂ = 142 g
reactants = CaCO₃ + HCl
products = CaCl₂ + CO₂ + H₂O
1.- Balanced chemical reaction
CaCO₃ + 2HCl ⇒ CaCl₂ + CO₂ + H₂O
2.- Limiting reactant
molar mass of CaCO₃ = 40 + 12 + 48 = 100 g
molar mass of HCl = 2[1 + 35.5 ] = 73 g
theoretical proportion CaCO₃ /HCl = 100 / 73 = 1.37
experimental proportion CaCO₃ /HCl = 155 / 250 = 0.62
As the experimental proportion was lower than the theoretical proportion the limiting reactant is CaCO₃
3.-
Calculate the molar mass of CaCl₂
CaCl₂ = 40 + 71 = 111 g
100 g of CaCO₃ ------------------ 111 g of CaCl₂
155 g of CaCO₃ ----------------- x
x = (155 x 111) / 100
x = 17205 / 100
x = 172.05 g of CaCl₂
4.- percent yield
Percent yield = 142 / 172.05 x 100 = 82.5 %
5.- Excess reactant
100 g of CaCO₃ -------------------- 73 g of HCl
155 g of caCO₃ ------------------- x
x = (155 x 73)/100
x = 133.15 g
Mass of HCl = 250 - 133.15
= 136.9 g
