1.38 moles of oxygen
Explanation:
Thermal decomposition of Lead (II) nitrate is shown by the balanced equation below;
2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂
The mole ration of Lead (II) nitrate to oxygen is 2: 1
Therefore 2.76 moles of Lead (II) nitrate will lead to production of? moles of oxygen;
2: 1
2.76: x
Cross-multiply;
2x = 2.76 * 1
x = 2.76 / 2
x = 1.38
Let x represent the total distance around the track
Jason's distance: (5/7)x
Sara ran (4/5) of Jason's distance,
so she ran (4/5)*(5/7)x = (4/7)x
Sara ran 4/7 of the total distance
Answer:

Explanation:
Hello there!
In this case, since the equation for the calculation of dilutions is:

Whereas M is the molarity and V the volume, because the final concentration is lower than the initial. Thus, since we are asked to calculate the final volume, we solve for V2 as follows:

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Answer:
[MgSO₄] = 890 mM/L
Explanation:
In order to determine molarity we need to determine the moles of solute that are in 1L of solution.
Solute: MgSO₄ (10.7 g)
Solvent: water
Solution: 100 mL as volume. (100 mL . 1L / 1000mL) = 0.1L
We convert the solute's mass to moles → 10.7 g / 120.36 g/mol = 0.089 moles
Molarity (mol/L) → 0.089 mol/0.1L = 0.89 M
In order to calculate M to mM/L, we make this conversion:
0.89 mol . 1000 mmoles/ 1 mol = 890 mmoles