Multiple Choice
Given a 0.300 M solution of HF, what concentration of NaF is required to achieve [H3O+] = 2.3 × 10^{-4} M? (Assume Ka for HF = 7.2 × 10^{-4} and that NaF fully dissociates.)
26
views
2. Atoms & Elements
Calculating Molar Mass
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
What is the molar mass of potassium nitrate (KNO_3)?
A
101.10 g/mol
B
85.11 g/mol
C
142.04 g/mol
D
39.10 g/mol
Verified step by step guidance1
Identify the chemical formula of potassium nitrate, which is KNO\_3.
Determine the atomic masses of each element from the periodic table: potassium (K), nitrogen (N), and oxygen (O).
Calculate the total mass contributed by each element by multiplying the atomic mass by the number of atoms in the formula: for K (1 atom), for N (1 atom), and for O (3 atoms).
Sum the masses of all elements to find the molar mass of KNO\_3 using the formula: \(\text{Molar mass} = (1 \times M_K) + (1 \times M_N) + (3 \times M_O)\).
Express the final molar mass in grams per mole (g/mol), which represents the mass of one mole of potassium nitrate.
Related Videos
Related Practice
Calculating Molar Mass practice set
Problem sets built by lead tutorsExpert video explanations