Answer:
1. Comparative
2. Independent variable
3. The pH is the Dependent variable
MgH2 + 2 H2O → Mg(OH)2 + 2 H2
Explanation:
1. Sedimentation and decantation cannot be used for all types of mixtures.
Decantation is a separation technique in which is used to separate immiscible liquids or mixtures containing liquid and solids within them.
In decantation, gravity is used to bring the denser materials to settle at the bottom.
For homogenous mixtures, it is not possible to use decantation. A solution of sugar and water will not decant.
2. Yes, mass of an object reduces the settling time of such object in a mixture.
The higher the mass, the faster the rate of settling. Also, as we know, mass is directly proportional to density. A body with a high density will settle faster in solution.
Answer:
50 mol
Explanation:
Mass of methane = 800 g
Number of moles of CO₂ produced = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of methane:
Number of moles = mass/molar mass
Number of moles = 800 g/ 16 g/mol
Number of moles = 50 mol
Now we will compare the moles of methane and carbon dioxide from balanced chemical equation.
CH₄ : CO₂
1 : 1
50 : 50
The molarity of aqueous lithium bromide, LiBr solution is 0.2 M
We'll begin by calculating the number of mole of Pb(NO₃)₂ in the solution.
- Volume = 10 mL = 10 / 1000 = 0.01 L
- Molarity of Pb(NO₃)₂ = 0.250 M
- Mole of Pb(NO₃)₂ =?
Mole = Molarity x Volume
Mole of Pb(NO₃)₂ = 0.25 × 0.01
Mole of Pb(NO₃)₂ = 0.0025 mole
Next, we shall determine the mole of LiBr required to react with 0.0025 mole of Pb(NO₃)₂
Pb(NO₃)₂ + 2LiBr —> PbBr₂ + 2LiNO₃
From the balanced equation above,
1 mole of Pb(NO₃)₂ reacted with 2 mole of LiBr.
Therefore,
0.0025 mole of Pb(NO₃)₂ will react with = 2 × 0.0025 = 0.005 mole of LiBr
Finally, we shall determine the molarity of the LiBr solution
- Mole = 0.005 mole
- Volume = 25 mL = 25 / 1000 = 0.025 L
- Molarity of LiBr =?
Molarity = mole / Volume
Molarity of LiBr = 0.005 / 0.025
Molarity of LiBr = 0.2 M
Learn more about molarity: brainly.com/question/10103895
