Answer:
2.8
Explanation:
First, we will calculate the molarity of the acetylsalicylic acid solution.
M = mass of solute (g) / molar mass of solute × volume of solution (L)
M = 0.327 g / 180.158 g/mol × 0.237 L
M = 7.66 × 10⁻³ M
For a weak acid such as acetylsalicylic acid, we can find the concentration of H⁺ using the following expression.
[H⁺] = √(Ca × Ka)
where,
Ca: concentration of the acid
Ka: acid dissociation constant
[H⁺] = √(7.66 × 10⁻³ × 3.3 × 10⁻⁴)
[H⁺] = 1.6 × 10⁻³ M
The pH is:
pH = -log [H⁺]
pH = -log 1.6 × 10⁻³ = 2.8
Answer:
pH = 1.6
Explanation:
0 mL NaOH:
⇒ [ H3O+] = M HBr = 0.1 M
⇒pH = -log [H3O+] = 1
30 mL NaOH:
⇒ mol NaOH = 0.1 mol / L * 0.03 L = 3 E-3 mol
⇒ mol HBr = 0.05 L * 0.1 mol/L = 5 E-3 mol
⇒ M HBr = ( 5 E-3 mol - 3 E-3 mol) / 0.08 L = 0.025 M
⇒ pH = - log (0.025) = 1.6
Answer:
The specific heat of the alloy 
Explanation:
Mass of an alloy 
= 25 gm
Initial temperature 
= 100°c = 373 K
Mass of water 
= 90 gm
Initial temperature of water 
= 25.32 °c = 298.32 K
Final temperature 
= 27.18 °c = 300.18 K
From energy balance equation
Heat lost by alloy = Heat gain by water
[ - ] = 
( - )
25 × × ( 373 - 300.18 ) = 90 × 4.2 (300.18 - 298.32)
This is the specific heat of the alloy.
Answer:
Extraction of aluminium
Aluminium ore is called bauxite . The bauxite is purified to produce aluminium oxide, a white powder from which aluminium can be extracted. The extraction is done by electrolysis. The ions in the aluminium oxide must be free to move so that electricity can pass through it.
