Answer:
<h2>6.41 %</h2>
Explanation:
The percentage error of a certain measurement can be found by using the formula

From the question
actual density = 7.80 g/cm³
error = 7.30 - 7.80 = 0.5
We have

We have the final answer as
<h3>6.41 %</h3>
Hope this helps you
Solutions with pH less than 7 are acidic in nature.
Therefore, a substance of pH 6 will be a weak acid.
Answer:
1.4 mols
4th answer
Explanation:
22. 5 g of O2 in moles = (22.5/32) mols = 0.703 mol
The stoichiometry between O2 and H2O =1: 2
Therefore H2O produced = 2 * 0.703 mols=1.406 mols
Answer:
0.11mol/dm³
Explanation:
The reaction expression is given as:
HCl + NaOH → NaCl + H₂O
Volume of acid = 25cm³ = 0.025dm³
Volume of base = 18.4cm³ = 0.0184dm³
Concentration of base = 0.15mol/dm³
Solution:
The concentration of hydrochloric acid = ?
To solve this problem, let us first find the number of moles of the base;
Number of moles = concentration x volume
Number of moles = 0.15mol/dm³ x 0.0184dm³ = 0.00276mol
From the balanced reaction equation;
1 mole of NaOH will combine with 1 mole of HCl
Therefore, 0.00276mol of the base will combine with 0.00276mol of HCl
So;
Concentration of acid =
=
= 0.11mol/dm³
Answer: 42.14 g
Explanation: calcium nitrate - 
, the molar mass of calcium nitrate = 164 g
<h3> formula used =

= no of moles </h3>
mass required =
=
g