Answer:
mass of Helium = mole of Helium x Molarmass of Helium
Explanation:
Mole of Helium = volume of Helium/ 22.4dm^3/mol
= 7.00 x 10^2/22.4
= 31.25mol
Mass of Helium = mole of Helium x Molarmass of Helium
= 31.25mol x 4g/mol
= 125g
Answer:
2 C₇H₅N₃O₆ + 10.5 O₂ → 14 CO₂ + 5 H₂O + 3 N₂
73.96 g
Explanation:
Trinitrotoluene (TNT), C₇H₅N₃O₆, combines explosively with O₂ to produce CO₂, H₂O, and N₂. The balanced equation is:
2 C₇H₅N₃O₆ + 10.5 O₂ → 14 CO₂ + 5 H₂O + 3 N₂
The molar mass of C₇H₅N₃O₆ is 227.13 g/mol and there are 2 moles in the balanced equation. Then, 2 × 227.13 g = 454.26 g participate in the reaction.
The molar mass of O₂ is 31.998 g/mol and there are 10.5 moles in the balanced equation. Then, 10.5 × 31.998 g = 335.98 g participate in the reaction.
The mass ratio of C₇H₅N₃O₆ to O₂ is 454.26 g:335.98 g. The mass of O₂ that reacts with 100.0 g of TNT is:
100.0 g C₇H₅N₃O₆ × (335.98 g O₂/454.26 g C₇H₅N₃O₆) = 73.96 g O₂
The answer would be C.Watt
The mass number represents the summation of the number of protons and the number of neutrons in the nucleus of an atom.
We are given that the mass number is 64 and that the number of neutrons is 35. Therefore:
number of protons = 64 - 35 = 29 protons
In ground state, number of protons in an atom is equal to the number of electrons. Therefore,
number of electrons = 29 electron
Using the periodic table, we will find that the element that has 29 electrons in ground state is copper.
The nuclide symbol of copper is shown in the attached image.