Answer:
Mixing of salt is physical change.
Explanation:
Mixing of salt is physical change because no chemical reaction occur between them. Sand is non polar while salt is polar.
Physical Change:
The changes that occur only due to change in shape or form but their chemical or internal composition remain unchanged.
These changes were reversible.
They have same chemical property.
These changes can be observed with naked eye.
Chemical change:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
These changes occur due to chemical reactions
These may not be observed with naked eye
Answer:
Octane is a hydrocarbon and an alkane with the chemical formula C 8 H 18, and the condensed structural formula CH 3 (CH 2) 6 CH 3.Octane has many structural isomers that differ by the amount and location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (commonly called iso-octane) is used as one of the standard values in the octane rating scale.
Chemical formula: C₈H₁₈
Molar mass: 114.232 g·mol−1
Melting point: −57.1 to −56.6 °C; −70.9 to −69.8 °F; 216.0 to 216.6 K
Solubility in water: 0.007 mg dm−3 (at 20 °C)
Answer:
Because there is trapped air inside the cube of ice
Explanation:
when water freezes it has water molecules and air molecules and as it freezes they move slower and slower until it freezes and they become stuck
The reaction between the reactants would be:
CH₃NH₂ + HCl ↔ CH₃NH₃⁺ + Cl⁻
Let the conjugate acid undergo hydrolysis. Then, apply the ICE approach.
CH₃NH₃⁺ + H₂O → H₃O⁺ + CH₃NH₂
I 0.11 0 0
C -x +x +x
E 0.11 - x x x
Ka = [H₃O⁺][CH₃NH₂]/[CH₃NH₃⁺]
Since the given information is Kb, let's find Ka in terms of Kb.
Ka = Kw/Kb, where Kw = 10⁻¹⁴
So,
Ka = 10⁻¹⁴/5×10⁻⁴ = 2×10⁻¹¹ = [H₃O⁺][CH₃NH₂]/[CH₃NH₃⁺]
2×10⁻¹¹ = [x][x]/[0.11-x]
Solving for x,
x = 1.483×10⁻⁶ = [H₃O⁺]
Since pH = -log[H₃O⁺],
pH = -log(1.483×10⁻⁶)
<em>pH = 5.83</em>
