Answer:
The element belongs to group 15 of the present periodic table
Explanation:
Isotopes have the same proton number, what differs is that they have different number of neutrons.
Now since the half-sum of their neutrons is 19, the total number of neutrons would be 19 * 2 = 38 neutrons.
Also, their masses add up to be 68, since the total mass equals sum of neutrons and sum of protons, this means that the total number of protons is 68-38 = 30
Since this is equal in both isotopes, this means that the proton number of the element is 30/2 = 15
The atomic number is the number of protons in the nucleus of an atom. Since the atomic number is 15, this element is phosphorus and it belongs to group 15 of the present periodic table
Answer:
The answer to your question is 6.0M, I know that you said it was not the answer, but it is. Check the significant figures.
Explanation:
Data
Molarity = ?
volume of HCl = 50 ml
volume of NaOH = 4 M
volume = 75 ml
Balanced chemical reaction
HCl + NaOH ⇒ NaCl + H₂O
Process
1.- Calculate the moles of NaOH
Molarity = moles/volume
moles = Molarity x volume
moles = 4 x 0.075
moles = 0.3 of NaOH
2.- Use proportions to calculate the moles of HCl
1 mol of NaOH ----------------- 1 mol of HCl
0.3 moles of NaOH ---------- x
x = (0.3 x 1)/1
x = 0.3 moles of HCl
3.- Calculate the molarity of HCl
Molarity = 0.3/0.05
Molarity = 6.0 M
Answer:
Theoretical yield for Si = 2586.55*28.09= 72.7 Kg
Percentage yield is =2356.71/2586.55=91.11%
Explanation:
So the chemical equation for this reaction would be SiO2 + 2C = Si + CO
so n(SiO2)=m(SiO2)/M(SiO2)=155400/60.08=2586.55 mol
n(C)=m(C)/M(C)=77400/12.01=6444.63 mol
So Carbon is in exes.
n(Si)=m(Si)/M(Si)=66200/28.09= 2356.71 mol
Theoretical yield for Si = 2586.55*28.09= 72.7 Kg
Percentage yield is =2356.71/2586.55=91.11%
Answer:
Option A. 2, 3, 2
Explanation:
We'll begin by balancing the equation. This can be achieved by doing the following:
Fe + Cl2 —> FeCl3
There are 2 atoms of Cl on the left side and 3 atoms on the right side. It can be balance by putting 3 in front of Cl2 and 2 in front of FeCl3 as shown below:
Fe + 3Cl2 —> 2FeCl3
There are 2 atoms of Fe on the right side and 1 atom on the left side. It can be balance by putting 2 in front of Fe as shown below:
2Fe + 3Cl2 —> 2FeCl3
Now the equation is balanced.
The coefficients are : 2, 3, 2
