The following answers:
1. B
2. D
Answer:
The correct option is: 2.50 g
Explanation:
Reaction involved: Mg(s) + 2 HCl(aq) → MgCl₂(aq) + H₂(g)
Molar mass: Mg = 24.305 g/mol, HCl = 36.461 g/mol
In the given reaction, 1 mole Mg reacts with 2 moles HCl.
Given: mass of HCl = 7.50 g
So, the number of moles of HCl = given mass ÷ molar mass = 7.50 g ÷ 36.461 g/mol = 0.2057 moles
Therefore, the<u> number of moles of Mg</u> that reacts with 0.2057 mole HCl = 0.2057 ÷ 2 = 0.1028 moles
Therefore, <u>the mass of Mg in grams</u> = molar mass × number of moles = 24.305 g/mol × 0.1028 mole = 2.5 g
Answer:
c) No, because Celsius is not an absolute temperature scale
Explanation:
converting 5 oC to kelvin which is the absolute temperature scale gives = 273 + 5 = 278 K
and converting 20 oC to kelvin = 20 + 273 = 293 K
the ratio = 278 / 293 = 0.94 approx 1 not 4
Answer:
warming up the solution.
Explanation:
- A saturated solution is a chemical solution containing the maximum concentration of a solute dissolved in the solvent. The additional solute will not dissolve in a saturated solution.
- Supersaturated solution is a solution that contains more of the dissolved material than could be dissolved by the solvent under normal circumstances.
- A saturated solution can become supersaturated when it is cooled.
- Also, we can form a saturated solution from a supersaturated solution via warming up the solution:
<em>The solubility of solid solutes in liquid solvents increases as the solvent is warmed up.</em>
Answer:
(A) 0.4M NaOH
Explanation:
The 20M NaOH caustic soda is diluted from 10mL to 500mL, that is:
500mL / 10mL = Is diluted 50 times.
That means we can solve the new concentration of the diluted solution dividing the stock concentration (20M) 50 times:
20M / 50 = 0.4M NaOH is the concentration of the diluted NaOH solution.
Right answer is:
<h3>(A) 0.4M NaOH</h3>
