When the guard cell is filled with water and it becomes turgid, the outer wall balloons outward, drawing the inner wall with it and causing the stomate to enlarge.
Combustible: Charcoal, straw, cardboard, paper, candle, wood.
Non-combustible: Chalk, stone, iron rod, copper coin, glass.
Answer:
Depending on the thermometer, it may have the ability to go as high or low as melting, freezing or boiling point for water. Just make sure you know the boiling, melting and freezing points in Celsius, Fahrenheit and/or Kelvin and read your thermometer accordingly.
Explanation:
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:
CH₃NH₃⁺ is a weak acid.
HPO₄²⁻ has a negligible acidity.
CH₄ has a negligible acidity.
HNO₂ is a weak acid.
Explanation:
There are 7 strong acids: HCl, HBr, HI, HNO₃, H₂SO₄, HClO₃, HClO₄. The rest of the acids are weak.
CH₃NH₃⁺ is a weak acid, according to the following equation:
CH₃NH₃⁺ ⇄ CH₃NH₂ + H⁺
HPO₄²⁻ can act as an acid or as a base:
<u>Acid reaction:</u> HPO₄²⁻ ⇄ PO₄³⁻ + H⁺
<u>Basic reaction:</u> HPO₄² + H₂O ⇄ H₂PO₄⁻ + OH⁻
Given Kb > Ka, HPO₄²⁻ has a negligible acidity.
CH₄ cannot release nor accept H⁺ so it has a negligible acidity.
HNO₂ is a weak acid, according to the following reaction:
HNO₂ ⇄ H⁺ + NO₂⁻
