5. B air is a mixture of many elements, but is not a chemically fused.
6. B Beef stew, composition varies throughout.
7. A. They can be chemically separated into their component elements, but they are all homogenous, and as such, have constant composition, which differs from the components properties, as the components must undergo a chemical change to become compounds.
The question is incomplete.
You need two additional data:
1) the original volume
2) what solution you added to change the volume.
This is a molarity problem, so remember molarity definition and formula:
M = n / V in liters: number of moles per liter of solution
To give you the key to answer this kind of questions, supppose the original volumen was 1 ml and that you added only water (solvent).
The original solution was:
V= 1 ml
M = 0.2 M
Using the formula for molarity, M = n / V
n = M×V = 0.2 M × (1 / 10000)l = 0.0002 moles
For the final solution:
n = 0.0002 moles
M = 0.04
From M = n / V ⇒ V = n / M = 0.002 moles / 0.04 M = 0.05 l
Change to ml ⇒ 0.05 l × 1000 ml / l = 50 ml. This would be the answer for the hypothetical problem that I assumed for you.
I hope this gives you all the cues you need to answer similar problems about molarity.
Yea! what the person underneath me said
Answer:
7.03 g
Explanation:
Step 1: Write the balanced synthesis reaction
N₂(g) + 3 H₂(g) ⇒ 2 NH₃(g)
Step 2: Calculate the moles corresponding to 32.5 g of N₂
The molar mass of N₂ is 28.01 g/mol.
32.5 g × 1 mol/28.01 g = 1.16 mol
Step 3: Calculate the number of moles of H₂ needed to react with 1.16 moles of N₂
The molar ratio of N₂ to H₂ is 1:3. The moles of H₂ needed are 3/1 × 1.16 mol = 3.48 mol.
Step 4: Calculate the mass corresponding to 3.48 moles of H₂
The molar mass of H₂ is 2.02 g/mol.
3.48 mol × 2.02 g/mol = 7.03 g
Answer is: the solution is saturated.
Solubility of potassium chloride (KCl) on 20°C is 34.2 grams in 100 grams of water, so in 200 grams of water will dissolve two times more salt (68.4 g).
Saturated solution contains the maximum concentration of a solute dissolved in the solvent (usually water) and if extra solute is add to saturated solution, that solute will not dissolve.
The amount of solute that can be dissolved in a solvent depends of chemical composition, temperature and pressure.