Answer:
The ion will repel the substance because it has lost two electrons.
Explanation:
An ion is a charged specie. We can see from the question that the ion has twelve positive and ten negative particles.
If there are more positive particles than negative particles, then the ion is positively charged.
If the ion is positively charged, it will repel another positively charged particle because like charges repel while opposite charges attract.
Answer:
A: Calcium is a group 2 element with two valence electrons. Therefore, it is very reactive and gives up electrons in chemical reactions. It is likely to react with an element with six valence electrons that “wants” to gain two electrons. This would be an element in group 6, such as oxygen.
Answer:
- The molarity of the student's sodium hydroxide solution is 0.0219 M
Explanation:
<u>1) Chemical reaction.</u>
a) Kind of reaction: neutralization
b) General form: acid + base → salt + water
c) Word equation:
- sodium hydroxide + oxalic acid → sodium oxalate + water
d) Chemical equation:
- NaOH + H₂C₂O₄ → Na₂C₂O₄ + H₂O
b) Balanced chemical equation:
- 2NaOH + H₂C₂O₄ → Na₂C₂O₄ + 2H₂O
<u>2) Mole ratio</u>
- 2mol Na OH : 1 mol H₂C₂O₄ :1 mol Na₂C₂O₄ : 2 mol H₂O
<u>3) Starting amount of oxalic acid</u>
- mass = 28 mg = 0.028 g
- molar mass = 90.03 g/mol
- Convert mass in grams to number of moles, n:
n = mass in grams / molar mass = 0.028 g / 90.03 g/mol = 0.000311 mol
<u>4) Titration</u>
- Volume of base: 28.4 mL = 0.0248 liter
- Concentration of base: x (unknwon)
- Number of moles of acid: 2.52 mol (calculated above)
- Proportion using the theoretical mole ratio (2mol Na OH : 1 mol H₂C₂O₄)
That means that there are 0.000622 moles of NaOH (solute)
<u>5) Molarity of NaOH solution</u>
- M = n / V (liter) = 0.000622 mol / 0.0284 liter = 0.0219 M
That is the correct number using <em>three signficant figures</em>, such as the starting data are reported.
Answer:
Second order
Explanation:
We could obtain the order of reaction by looking at the table very closely.
Now notice that in experiment 1 and 2, the concentration of [OH^-] was held constant while the concentration of [S8] was varied. So we have;
a situation in which the rate of reaction was tripled;
0.3/0.1 = 2.10/0.699
3^1 = 3^1
Therefore the order of reaction with respect to [S8] is 1.
For [OH^-], we have to look at experiment 2 and 3 where the concentration of [S8] was held constant;
x/0.01 = 4.19/2.10
x/0.01 = 2
x = 2 * 0.01
x = 0.02
So we have;
0.02/0.01 = 2^1
2^1 = 2^1
The order of reaction with respect to [OH^-] = 1
So we have the overall rate law as;
Rate = k[S8]^1 [OH^-] ^1
Overall order of reaction = 1 + 1 = 2
Therefore the reaction is second order.
Answer:
3. 76 g/ml^3
Explanation:
We are given the mass of the metal pellets which is 33.4 grams. To calculate the density of the metal, we need to divide the mass by the volume. The volume of the metal is not directly given so we need to find it ourselves. The water was initially 12.7 ml and then it rose to 21.6 ml after placing the metal pellets. This indicate that the volume of the metal pellets is 8.9 ml.
We can now use the density formula.