1) Chemical equation:
Mg + O2 -> MgO
2) Balanced chemical equation:
2Mg + O2 -> 2MgO
3) Ratios
2 mol Mg : 1 mol O2 : 2 mol MgO
4) Convert 2 grams of Mg to number of moles
Molar mass of Mg: 24.3 g/mol
# of moles = grams / molar mass = 2g / 24.3 g/mol = 0.0823 mol
5) Use the theoretical ratio fo find the number of moles of MgO produced
0.0823 mol Mg * 2mol MgO / 2 mol Mg = 0.0823 mol MgO
6) Use the molar mass of MgO to obtain the quantity in grams
Molar mass of MgO = 24.3 g/mol + 16 g/mol = 40.3 g/mol
0.0823 mol MgO * 40.3 g/ mol = 3.32 g
Answer: 3.32 g
You would place it in orbit around Earth, as most X-rays are absorbed by the atmosphere, so you would want the detector outside of the atmosphere to accurately detect the X-rays.
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
C. Magnesium and Calcium is my best guess because they are in the same group or family and they are in the <span>alkaline earth metals.</span>