Answer:
D. They have the same number of valence electrons
Explanation:
- The periodic table arranges elements into rows known as periods and columns known as groups or families.
- Elements in the same group share similar chemical properties.
- Additionally, they have the same number of valence electrons. For example, elements in group I have one valence electrons while those in group II have two valence electrons.
- Elements in the same period share similar features such as having the same number of energy levels. For example elements in period 4 have four energy levels.
Answer:
The correct answer is 17 meq/g
Explanation:
Ion exchange capacity (IEC) express the total of active sites of a resin in which ions are attached because the greater molecular weight.
The exchange Reaction can be represented as
R-H
The IEC value (in meq/g) is determinated by using the next equation:
IEC=[(mL of NaOH)*(M of NaOH)]/mass of resin
IEC [(17 mL)*(0.5 M)/0.5]= 17 meq/g
Stoichiometry:
First, calculate the number of grams for one mole of Ca3 (PO3)4
(3 * (Mass of Ca)) + (4 * (Mass of P + (3 * Mass of Oxygen)))
= (3*40.08) + 4(30.97 + (3*16.00))
=(120.24) + 4(78.97)
=436.12 g / mol Ca3(PO3)4
This means there are 436.12 g per 1 mole of Ca(PO3)4. Since there are 4.50 moles of Calcium Phosphate, mulitply the molar mass of Ca(PO3)4 by 4.50 and you should get 1962.54 g. Since there are 3 sigfigs, the final answer is 1960 g.
on a side note: I put in all my work in case 1. your periodic table if different, 2. my work is wrong, 3. you put in the question wrong because I feel that the actual compound would be Ca3(PO4)3 instead of Ca3(PO3)4 (if this is the case, the answer should be 1820 g).
Answer:
The units of the rate constant, k, depend on the overall reaction order. The units of k for a zero-order reaction are M/s, the units of k for a first-order reaction are 1/s, and the units of k for a second-order reaction are 1/(M·s).
Explanation:
