Answer:
Molar mass = 0.09 × 10⁴ g/mol
Explanation:
Given data:
Mass = 0.582 g
Volume = 21.3 mL
Temperature = 100°C
Pressure = 754 mmHg
Molar mass = ?
Solution:
(21.3 /1000 = 0.0213 L)
(100+273= 373 K)
(754/760 = 0.99 atm)
PV = nRT
n = PV/RT
n = 0.99 atm × 0.0213 L / 0.0821 atm. L. mol⁻¹. k⁻¹ × 373 K
n =0.02 mol/ 30.6
n = 6.5 × 10⁻⁴ mol
Molar mass = Mass/ number of moles
Molar mass = 0.582 g / 6.5 × 10⁻⁴ mol
Molar mass = 0.09 × 10⁴ g/mol
Answer:
Hydronium ion concentrations increase with decreasing pH values. So, the solutions with the lower pH values have the higher H₃O⁺ concentrations.
Explanation:
Answer:
Atomic number, the number of a chemical element in the periodic system, whereby the elements are arranged in order of increasing number of protons in the nucleus. Accordingly, the number of protons, which is always equal to the number of electrons in the neutral atom, is also the atomic number.
Explanation:
Answer:
Mass = 7.2 g
Explanation:
Given data:
Mass of ZnO = 36.9 g
Mass of oxygen needed = ?
Solution:
Chemical equation:
2Zn + O₂ → 2ZnO
Number of moles of ZnO:
Number of moles = Mass/ molar mass
Number of moles = 36.9 g/81.38 g/mol
Number of moles = 0.45 mol
Now we will compare the moles of ZnO with oxygen:
ZnO : O₂
2 : 1
0.45 : 1/2 × 0.45 = 0.225
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 0.225 mol × 32 g/mol
Mass = 7.2 g
