Molar mass:
KCl = 74.55 g/mol
KClO3 = 122. 55 g/mol
<span>Calculation of the mass of KClO3 :</span>
<span>2 KClO3 = 2 KCl + 3 O2</span>
2* 122.55 g KClO3 ------------------ 2 * 74.55 g KCl
mass KClO3 ?? --------------------- 25.6 g KCl
mass KClO3 = 25.6 * 2 * 122.55 / 2 * 74.55
mass KClO3 = 6274.56 / 149.1
mass = 42.082 g of KClO3
Therefore:
1 mole KClO3 ---------------------- 122.55 g
?? moles KClO3 ------------------- 42.082 g
moles KClO3 = 42.082 * 1 / 122.55
moles KClO3 = 42.082 / 122.55
=> 0.343 moles of KClO3
Answer C
hope this helps!
Answer: The frequency of the wave is 0.5 hertz.
Explanation:
= Frequency of the wave
= speed of the light in m/s
= Wavelength of the wave.
Here in question we are given with speed of the infrared light. So, we will replace the value of speed of light(c) from the given value of the speed of the infrared light.
Speed of infrared light = 6 m/s
The frequency of the wave is 0.5 hertz.
Answer:
pH = 4.34
Explanation:
pH= -1/2(logKa) -1/2(log C)
= -1/2( log 5.98*10^-8) -1/2(log 0.0353)
=-1/2(-7.22)-1/2(-1.45)
=3.61+0.725= 4.34
Answer:
0.109 g.
Explanation:
Equation of the reaction:
Na3PO4 + 3HCl --> 3NaCl + H3PO4
Number of moles of HCl = molar concentration × volume
= 0.1 × 0.04
= 0.004 mol.
By stoichiometry, 1 mole of Na3PO4 neutralises 3 moles of HCl. Therefore, number of moles of Na3PO4 = 0.004/3
= 0.0013 mol
Mass of Na3PO4 = molar mass × number of moles
= 0.0013 × 164
= 0.219 g
Since 50% of Na3PO4 was present in the sample. Let 100 g be the total mass of the substance
= 0.219 × 50 g/100 g
= 0.109 g.
Percentage by volume of solution is the percentage volume of solute in total volume of solution.
Volume percentage (v/v%) = volume of solute / total volume of solution x 100%
volume of solute - 16.0 mL
total volume of solution - 155 mL
v/v% = 16.0 / 155 x 100% = 10.32%
this means that in a volume of 100 mL solution, 10.32 mL is acetone.
