Answer:
The atomic number on the Periodic Table identifies the number of protons in any atom of that element. Copper, atomic number 29, has 29 protons. Finding the atomic number of an element reveals the number of protons.
To find the number of neutrons in the atom, subtract the atomic number from the atomic mass.
Answer:
Sulfur would gain electrons
Explanation:
Atoms want to have a complete out valence shell and because sulfur only needs 2 more electrons to complete the outer shell it would take 2 more.
From the periodic table:
mass of carbon = 12 grams
mass of hydrogen = 1 gram
mass of nitrogen = 14 grams
mass of oxygen = 16 grams
mass of chlorine = 35.5 grams
Therefore,
molar mass of <span>c17h22clno4 = 17(12) + 22(1) + 35.5 + 14 + 4(16) = 339.5 grams
number of moles = mass / molar mass
number of moles = (23*10^-3) / (339.5)
number of moles = 6.77 * 10^-5 moles
number of atoms = number of moles * Avogadro's number
number of atoms = 6.77*10^-5 * 6.022*10^-23
number of atoms = 4.079 * 10^-27 atoms</span>
Answer:
3 × 10⁴ kJ
Explanation:
Step 1: Write the balanced thermochemical equation
C₃H₈(g) + 5 O₂(g) ⟶ 3 CO₂(g) + 4 H₂O(g) ΔH = -2220 kJ
Step 2: Calculate the moles corresponding to 865.9 g of H₂O
The molar mass of H₂O is 18.02 g/mol.
865.9 g × 1 mol/18.02 g = 48.05 mol
Step 3: Calculate the heat produced when 48.05 moles of H₂O are produced
According to the thermochemical equation, 2220 kJ of heat are evolved when 4 moles of H₂O are produced.
48.05 mol × 2220 kJ/4 mol = 2.667 × 10⁴ kJ ≈ 3 × 10⁴ kJ
