A chemical change is characterized of the formation of new substances or a chemical reaction. There are a number of observations that we can see if this type of change happens. One would be the formation of gas bubbles, this indicates that one of the products is a gas. Another observation would be a formation of a precipitate in the solution, it would indicate that the new solid formed is not soluble in the solution. A permanent color change in the solution would also indicate a chemical change because it may be that the new substance that is formed has its own distinct color when in solution.

6 0

3 years ago

Identify the products in the following chemical resction 2NaHCO3 + CaCI2 --> CaCO3 + CO2 + 2NaCI + H2O

Radda [10]

the products are:

CaCO3 Calcium Carbonate

CO2 carbon dioxide

NaCI Sodium chloride

H2O Water

8 0

3 years ago

Which has the highest boiling point .33 m NH3 or .10 m Na2SO4

Aleksandr-060686 [28]

Answer:

0.33 mol/kg NH₃

Explanation:

Data:

b(NH₃) = 0.33 mol/kg

b(Na₂SO₄) = 0.10 mol/ kg

Calculations:

The formula for the boiling point elevation ΔTb is

$\Delta T_{b} = iK_{b}b$

i is the van’t Hoff factor — the number of moles of particles you get from a solute.

(a) For NH₃,

The ammonia is a weak electrolyte, so it exists almost entirely as molecules in solution.

1 mol NH₃ ⟶ 1 mol particles

i ≈ 1, and ib = 1 × 0.33 = 0.33 mol particles per kilogram of water

(b) For Na₂SO₄,

Na₂SO₄(aq) ⟶ 2Na⁺(aq) + 2SO₄²⁻(aq)

1 mol Na₂SO₄ ⟶ 3 mol particles

i = 1 and ib = 3 × 0.10 = 0.30 mol particles per kilogram of water

The NH₃ has more moles of particles, so it has the higher boiling point.

5 0

3 years ago