A volumetric flask is used to contain a predetermined volume of substance and only measures that volume, for example 250 ml.
Conical flasks can be used to measure the volume of substances but the accuracy they provide is usually up to 10ml. Conical flasks are used in titrations, reactions where the liquid may boil, and reactions which involve stirring.
Pippettes are of two types, volumetric and graduated. Pippettes are used where high accuracy is required and volumetric pippettes come in as little as 1 ml. Pippettes are usually used in titrations.
Graduated cylinders come in a wide variety of sizes and their accuracy can be down to as much as 1 ml. They are used to contain liquids.
Initial moles of C₆H₅COOH = 500/1000 × 0.10 = 0.05mol
Initial moles of C₆H₅COONa = 500/1000 × 0.10 = 0.05 mol
initial pH = Pka + log([C₆H₅COONa/ moles of C₆H₅COOH)
4.19 = pKa + log(0.05/0.05)
→pKa = 4.19
C₆H₅COOH + NaOH → C₆H₅COONa ₊ H₂o
moles of NaOH added = 0.010 mol
moles of C₆H₅COOH = 0.05 - 0.025 = 0.025 mol
Final pH = pKa + log([C₆H₅COONa)/[ C₆H₅COOH])
=pKa + log(moles of C₆H₅COONa/moles of C₆H₅COOH)
= 4.19 + log(0.025/0.075)
4.29
The answer is strontium dihydrogen phosphate
That is strontium dihydrogen phosphate, is the compound containing the most hydrogen atoms per molecule or formula unit.
The formulas of the following compounds are as follows:
Hydrogen selenide H₂Se
Ammonium bromide NH₃Br
Strontium dihydrogen phosphate Sr(H₂PO4)₂
Sodium bicarbonate NaHCO₃
As it can be seen from the formula of strontium dihydrogen phosphate Sr(H₂PO4)₂
, that it contains the most hydrogen atoms per molecule or formula unit.
Molar mass O₂ = 32.0 g/mol and N₂ = 28.0 g/mol
N₂ +2 O₂ → 2 NO₂
28.0 g -------> 32.0 * 2
7 g ----------> ?
Mass of O₂ = 7 * 32.0 * 2 / 28.0
Mass of O₂ = 448 / 28.0
= 16 g of O₂
Answer B
hope this helps!
