# What happens if you add HCl to NaHCO3

1. Oct 9, 2007

### bhummel

1. The problem statement, all variables and given/known data
can anyone answer these questions what happens if you add HCl to NaHCO3 also what happens if you add HCl to magnesium and HCl to burnt magnesium what do these tests mean? also how many significant figures can you obtain with the centigram balance and with the electronic balance. If someone can help please

2. Relevant equations

3. The attempt at a solution

2. Oct 9, 2007

### eli64

1st and 3rd one - these have to do with exchanging ions of AB + CD ---> AD and CB (double replacement or methathesis reactions). What is the compound that is made after Mg is burned in air?

2nd one is exchanging AB + C ----> AC + B

these are the relevant equations,

centigram balance - how many decimal places is this?
electronic balance can vary depending on if it is a lab balance or an analytical (very sensitive) balance

3. Oct 9, 2007

### bhummel

thank you maybe you can also help me with these. In the following total ionic equation, which ions are spectators Cu2+(aq)+2Na+(aq)+S2-(aq)--->CS(s)+2NO-3(aq)+2Na+(aq)
answers a)CU2+ b)Na+ c)NO-3 d)S2- aould this be CuS because it is a solid?
Also Suppose you tried to carry out a double replacement reaction by mixing together equalvoulumes of a solution that contains dissolved NaOH and a solution that contains dissolved NaCl. what would you expect to happen when the two solutions mixed? a) Asolid would form b Asolid would not form I think it would not

4. Oct 9, 2007

### bhummel

chemistry

5. Oct 10, 2007

### eli64

with HCl and NaHCO3, these compounds dissociate in solution in the form of

AB + CD ---> AC + BD
A+ + B- + C+ + D- ----> rearrage to exchange partners AD + CB

H+(aq) + Cl-(aq) + Na+(aq) + HCO3-(aq) ---> how would you rearrage to get products?

6. Oct 10, 2007

### eli64

The number of sigfigs depends on what is on the balance. If you are talking about precision then if it is a centigram balance, the precision is to 0.01g. If nothing is on the balance and it reads 0.00g - how many sig figs is this? If you have a beaker on the balance that has a mass of 150.00 g, how many sig figs is this?

same for the electronic balance and its precision, which is what I meant by "it can vary". Some are precise to 0.001 or 0.0001 g.

I think the question is probably referring to, how many decimal places are significant on these balances.

7. Oct 10, 2007

### eli64

look at this again, I think you have missed an ion on the left hand side. Also what is the definition of a spectator ion? review this and it may help you to work it out better.