Answer:
2.7724 g
Explanation:
Mass of pre- 1892 pennies = 3.1 g
Abundance = 45.4 %
Mass of post 1892 pennies = 2.5 g
Abundance = 100 - 45.4 = 54.6 %
The average mass is given as = ( 3.1 g * 45.4 / 100) + (2.5g * 54.6 / 100)
Average Mass = 3.1 * 0.454 + 2.5 * 0.546
Average Mass = 1.4074 + 1.365 = 2.7724 g
27/208 = normality
12 x 10^-2 approx = normality
nw Ka = 14.3 x 10^-3
pKa = 3 - log 14
now, after getting the pKa put it in formula :
pH = pKa + log concn of ion/concn of salt and you'll get it
hope this helps
Answer:
2600 kg has 4 significant figures
Explanation:
Any different number to zero is a significant figure
For example, 1.8 → 2 significant figures
When you have 0 in the middle of two numbers, we consider it as a significant number
For example, 3.02 → 3 significant figures
When you have 0 on the left in the measure, we do not consider as a sgnificant figures
For example 0.0010 → 2 significant figures (10)
3.0 → 2 significant figures (0 is on the right, not the left)
56% percent is the answer
