Which of the following is a correctly balanced reaction equation?
-CaCl2+ NaOH -> NaCl2+ Ca(OH)
-CaCl2 + 2NaOH -> 2NaCl + Ca(OH)2
-CaCl2 + NaOH -> NaCI + Ca(OH)2
-2CaCl2 + 4NaOH -> 4NaCl + 2Ca(OH)2
4 answers
just make sure each atom present has the same amount on both sides of the equation.
Everyone says that. How am I supposed to know
You count them. That's all there is to it. Here are the equations. Here is what I would do.
1. CaCl2+ NaOH -> NaCl2+ Ca(OH)
You know #1 can't be right BECAUSE NaCl2 should be NaCl so counting isn't necessary.
2. CaCl2 + 2NaOH -> 2NaCl + Ca(OH)2
Looks like the formula are OK so let's count atoms.
I see 1 Ca on the left in CaCl2 and 1 on the right in Ca(OH)2. I see 2 Cl on the left in CaCl2 and 2 on the right in 2NaCl. I see 2 Na on the left in 2NaOH and 2 on the right in 2NaCl. I see 2 OH on the left (or 2O and 2H in 2NaOH) and 2 on the right in Ca(OH)2 [or
2O and 2H in Ca(OH)2 on the right]. Everything checks out. This must be the correct one but I would look at the others also.
3. CaCl2 + NaOH -> NaCI + Ca(OH)2
I see 1 Ca on the left in CaCl2 and 1 on the right in Ca(OH)2. I see 2 Cl on the left in CaCl2 but just 1 on the right in NaCl. No need to count further. #3 can't be right.>
4. 2CaCl2 + 4NaOH -> 4NaCl + 2Ca(OH)2
Now that you see how it's done I won't go through this one; however, I hope you will. You will see that IT IS BALANCED. Technically, you might try to argue that this question has two answers but it doesn't BECAUSE the question is "Which of the following is a CORRECTLY balanced reaction equation? A CORRECTLY balanced equation not only has the same atoms on both sides of the equation BUT the coefficients must be the SMALLEST set of numbers. This last one is just double the correct equation which is #2. Hope this helps.
1. CaCl2+ NaOH -> NaCl2+ Ca(OH)
You know #1 can't be right BECAUSE NaCl2 should be NaCl so counting isn't necessary.
2. CaCl2 + 2NaOH -> 2NaCl + Ca(OH)2
Looks like the formula are OK so let's count atoms.
I see 1 Ca on the left in CaCl2 and 1 on the right in Ca(OH)2. I see 2 Cl on the left in CaCl2 and 2 on the right in 2NaCl. I see 2 Na on the left in 2NaOH and 2 on the right in 2NaCl. I see 2 OH on the left (or 2O and 2H in 2NaOH) and 2 on the right in Ca(OH)2 [or
2O and 2H in Ca(OH)2 on the right]. Everything checks out. This must be the correct one but I would look at the others also.
3. CaCl2 + NaOH -> NaCI + Ca(OH)2
I see 1 Ca on the left in CaCl2 and 1 on the right in Ca(OH)2. I see 2 Cl on the left in CaCl2 but just 1 on the right in NaCl. No need to count further. #3 can't be right.>
4. 2CaCl2 + 4NaOH -> 4NaCl + 2Ca(OH)2
Now that you see how it's done I won't go through this one; however, I hope you will. You will see that IT IS BALANCED. Technically, you might try to argue that this question has two answers but it doesn't BECAUSE the question is "Which of the following is a CORRECTLY balanced reaction equation? A CORRECTLY balanced equation not only has the same atoms on both sides of the equation BUT the coefficients must be the SMALLEST set of numbers. This last one is just double the correct equation which is #2. Hope this helps.
“This last one is just double the correct equation which is #2.” I don’t understand this. So is #2 or #4 the correct answer?
1 answer