Answer: Cotton
Explanation: Some cement is natural but i don't think that's what question is referring to. C: polyester is made from synthetic fibers. D: nylon is man made.
Also, cotton grows on plants.
The reaction between NaOH and HCl is as follows
NaOH + HCl ---> NaCl + H₂O
for neutralisation, H⁺ ions react with an equivalent amount of OH⁻ ions.
Number of NaOH moles reacted = 0.270 M/1000 mL/L x 37 mL = 0.00999 mol
number of HCl moles reacted = 0.270 M/1000 mL x 27 mL = 0.00729 mol
HCl reacts with NaOH in 1:1 molar ratio
Number of excess NaOH moles remaining - 0.00999 - 0.00729 = 0.0027 mol
total volume of solution = 37 mL + 27 mL = 64 mL = 0.064 L
Since there's excess OH⁻ ions, we can calculate pOH value first
pOH = - log [OH⁻]
[OH⁻] = 0.0027 mol / 0.064 L = 0.042 mol/L
pOH = -log(0.042 M)
pOH = 1.37
by knowing pOH we can calculate pH using the following equation;
pH + pOH = 14
pH = 14 - 1.37
pH = 12.63
Answer:
6.6023g
Explanation:
To create a 0.247 M solution required weight of barium hydroxide.
0.247 x 171.346 =42.322g per liter
Therefore required mass for 156g of water = 42.322 x 0.156 = 6.6023g
I have written the answer in the comments i hope it will be helpful to you ......
