Answer:
All of the above.
Explanation:
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances.
This process is not reversible and a change of energy that is sometimes heat is given off.
Answer:
Friction
Explanation:
Friction is the name of the force that opposes motion.
Answer:
Option a.
0.01 mol of CaCl₂ will have the greatest effect on the colligative properties, because it has the biggest i
Explanation:
To determine which of the solute is going to have a greatest effect on colligative properties we have to consider the Van't Hoff factor (i)
These are the colligative properties:
ΔP = P° . Xm . i → Lowering vapor pressure
ΔT = Kb . m . i → Boiling point elevation
ΔT = Kf . m . i → Freezing point depression
π = M . R . T → Osmotic pressure
Van't Hoff factor are the numbers of ions dissolved in the solution. For nonelectrolytes, the i values 1.
CaCl₂ and KNO₃ are two ionic solutes. They dissociate as this:
CaCl₂ → Ca²⁺ + 2Cl⁻
We have 1 mol of Ca²⁺ and 2 chlorides, so 3 moles of ions → i = 3
KNO₃ → K⁺ + NO₃⁻
We have 1 mol of K⁺ and 1 mol of nitrate, so 2 moles of ions → i = 2
Option a, is the best.
Answer:
Explanation:
First we need to find how many moles of ammonium weigh 62 grams.
Molar mass of NH4 = (14.0)+(4*1.0) grams
or 18.0 grams/mole
62 (g)/18(g/mole) = 3.444... moles of NH4
If it is dissolved in 5 litres of water, the concentration will be 3.444moles/5L
or 0.6888 M.
