Answer:
(1) 0.0016 mol/L
Explanation:
Let the concentration of alcohol after 3.5 hours be y M
The reaction follows a first-order
Rate = ky^0 = change in concentration/time
k = 6.4×10^-5 mol/L.min
Initial concentration = 0.015 M
Concentration after 3.5 hours = y M
Time = 3.5 hours = 3.5×60 = 210 min
6.4×10^-5y^0 = 0.015-y/210
y^0 = 1
0.015-y = 6.4×10^-5 × 210
0.015-y = 0.01344
y = 0.015 - 0.01344 = 0.00156 = 0.0016 mol/L (to 4 decimal places)
Answer:
Partial pressure of oxygen = 23.38 kpa (Approx)
Explanation:
Given:
Amount of oxygen = 23.15%
Amount of nitrogen = 76.85%
Pressure (missing) = 101 kpa
Find:
Partial pressure of oxygen
Computation:
Partial pressure of oxygen = [Amount of oxygen x Pressure]/100
Partial pressure of oxygen = [23.15% x 101]/100
Partial pressure of oxygen = 23.38 kpa (Approx)
This is a physical change, you can turn the current off not changing something permanently such as mixing cake batter you cant delude the eggs and flour so its would be physical.
Answer:
1.75 × 10⁻³ M
Explanation:
Given:
Hardness = 175 mg CaCO₃/L
or mass of CaCO₃ in 1 L = 175 × 10⁻³ grams
Now,
Molar mass of CaCO₃ = 40 + 12 + ( 3 × 12 ) = 100 grams/mol
The concentration of CaCO₃ = number of moles / volume
or
= (175 × 10⁻³ / 100) / 1
or
= 1.75 × 10⁻³ M
Now,
CaCO₃ ⇒ Ca²⁺ + CO₃²⁻
1.75 × 10⁻³ M 1.75 × 10⁻³ M 1.75 × 10⁻³ M
thus,
the concentration of Ca²⁺ ions in water = 1.75 × 10⁻³ M
