Again great job! They all look correct except 20. is 3.7 due to sig fig of least precision, which you have a mark by!! You don't even need help!;) Here comes the next chemical engineer! :)
Answer:
0.033 M
Explanation:
Let's consider the neutralization reaction between NaOH and HCl.
NaOH + HCl → NaCl + H₂O
0.4 L of 0.1 M NaOH were used. The reacting moles of NaOH are:
0.4 L × 0.1 mol/L = 0.04 mol
The molar ratio of NaOH to HCl is 1:1. The reacting moles of HCl are 0.04 moles.
0.04 moles of HCl are in 1.2 L. The molarity of HCl is:
M = 0.04 mol / 1.2 L = 0.033 M
Answer:
390 m
Explanation:
Martha ran 420 m
Cole ran 60 m less than Martha = 420 m - 60 m = 360 m
The distance Kate ran is right in the middle of Martha and Cole's distances
Kate distance = (420 + 360) / 2 = 780 / 2 = 390 m
Answer:
3.052 × 10^24 particles
Explanation:
To get the number of particles (nA) in a substance, we multiply the number of moles of the substance by Avogadro's number (6.02 × 10^23)
The mass of Li2O given in this question is as follows: 151grams.
To convert this mass value to moles, we use;
moles = mass/molar mass
Molar mass of Li2O = 6.9(2) + 16
= 13.8 + 16
= 29.8g/mol
Mole = 151/29.8g
mole = 5.07moles
number of particles (nA) of Li2O = 5.07 × 6.02 × 10^23
= 30.52 × 10^23
= 3.052 × 10^24 particles.
