Answer:
The mass of copper = 208.26 grams.
Explanation:
Density = mass / volume
8.9 = mass / 23.4
mass = 8.9 * 23.4
= 208.26 grams.
Answer:
3.0 × 10²⁰ molecules
Explanation:
Given data:
Mass of ethanol = 2.3 × 10⁻²°³ g
Number of molecules = ?
Solution:
Number of moles of ethanol:
Number of moles = mass/ molar mass
Number of moles = 2.3 × 10⁻²°³ g / 46.07 g/mol
Number of moles = 0.05 × 10⁻²°³ mol
Number of molecules:
One mole = 6.022 × 10²³ molecules
0.05 × 10⁻²°³ mol × 6.022 × 10²³ molecules / 1 mol
0.30 × 10²⁰°⁷ molecules
3.0 × 10¹⁹°⁷ molecules which is almost equal to 3.0 × 10²⁰ molecules.
Answer:
molar mass M(s) = 65.326 g/mol
Explanation:
- M(s) + H2SO4(aq) → MSO4(aq) + H2(g)
∴ VH2(g) = 231 mL = 0.231 L
∴ P atm = 1.0079 bar
∴ PvH2O(25°C) = 0.03167 bar
Graham´s law:
⇒ PH2(g) = P atm - PvH2O(25°C)
⇒ PH2(g) = 1.0079 bar - 0.03167 bar = 0.97623 bar = 0.9635 atm
∴ nH2(g) = PV/RT
⇒ nH2(g) = ((0.9635 atm)(0.231 L))/((0.082 atmL/Kmol)(298 K))
⇒ nH2(g) = 9.1082 E-3 mol
⇒ n M(s) = ( 9.1082 E-3 mol H2(g) )(mol M(s)/mol H2(g))
⇒ n M(s) = 9.1082 E-3 mol
∴ molar mass M(s) [=] g/mol
⇒ molar mass M(s) = (0.595 g) / (9.1082 E-3 mol)
⇒ molar mass M(s) = 65.326 g/mol
Explanation:
5g C7H8 / 92g/mole = 0.054moles
total moles = 0.232moles
mole fraction C6H12 = 0.178moles / 0.232moles = 0.767
mole fraction C7H8 = 0.233
