Answer:
10.5grams
Step-by-step explanation:
Molarity = number of moles (n)/ volume (V)
According to this question;
Volume = 750 mL = 750/1000 = 0.75L
Molarity = 0.35M
number of moles (n) = molarity × volume
n = 0.35 × 0.75
n = 0.2625mol
Using mole = mass/molar mass
Molar Mass of NaOH = 23 + 16 + 1
= 40g/mol
mole = mass/molar mass
0.2625 = mass/40
mass = 10.5grams
10.5 grams are needed to prepare 0.75L of a 0.35 M solution of NaOH.