In the combustion process using excess oxygen, each mole of methane results to 1 mole of co2 while ethane produces 2 moles of Co2. Under same conditions, these can be translated to volume. Hence the total volume absorbed is 10 cm3 + 20 cm3 = 30 cm3.
Answer:
Learn from their experiment and know the possible results from trial and error
This is an acid base reaction and the chemical equation for the above reaction is as follows;
KOH + HClO₄ ---> KClO₄ + H₂O
the stoichiometry of acid to base is 1:1
KOH is a strong base and HClO₄ is a strong acid therefore they both ionize completely into their respective ions
Number of KOH moles - 0.723 M/1000 mL/L x 25.0 mL = 0.018 mol
Number of HClO₄ moles - 0.273 M/1000 mL/L x 50 mL = 0.013 mol
since acid and base react completely, 0.013 mol of acid reacts with 0.013 mol of base.
The excess base remaining is - 0.018 - 0.013 = 0.005 mol
total volume of solution = 25.0 mL + 50.0 mL = 75.0 mL
[OH⁻] = 0.005 mol/0.075 L = 0.067 M
pOH = -log[OH⁻]
pOH = -log(0.067 M)
pOH = 1.17
pOH + pH = 14
Therefore pH = 14 - 1.17 = 12.83
by knowing pH we can calculate the [H₃O⁺]
pH = -log [H₃O⁺]
[H₃O⁺] = antilog[-12.83]
[H₃O⁺]= 1.47 x 10⁻¹³ M
calculation of the volume displaced in the cylinder:
Volume final - Volume initial
62.4 mL - 50.0 mL = 12.4 mL
Mass of metal = 48.0 g
Therefore:
D = m / V
D = 48.0 / 12.4
D = 3.87 g/mL
Hope that helps!
Answer:
126.86
Explanation:
Given parameters:
1x - percent abundance = 80%(0.8), mass = 127
2x - percent abundance = 17%(0.17), mass = 126
3x - percent abundance = 3%(0.03) , mass = 128
Unknown:
Average atomic mass = ?
Solution:
The average atomic mass is the average of all isotopes of element. It can be calculated using the expression below;
RAM = (mass x abundance of 1x) + (mass x abundance of 2x) + (mass x abundance of 3x)
Now insert the parameters and solve;
RAM = (127 x 0.8) + (126 x 0.17) + (128 x 0.03) = 126.86
