# Chemistry

A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard solution is assumed to be ____ M.

I tried this problem by adding the moles of Fe(NO3)3 and KSCN and dividing that by 0.01 L. I got 0.1802 but it's wrong.

1. 👍 0
2. 👎 0
3. 👁 204
1. Write the equation to see what is going on.
Fe(NO3)3 + KSCN ==> FeSCN^+2 + 3NO3^-

mols Fe(NO3)3 = M x L = ??
mols KSCN = M x L = ??
Use the equation to make an educated guess about the FeSCN^+2. Without doing any of the math it is obvious that the KSCN is there is MUCH lesser quantity (said another way the KSCN is the limiting reagent); therefore, mols FeSCN^+2 = mols KSCN. then (FeSCN^+2) = mols FeSCN^+2/liters. Note that the final volume is 10 mL = 0.010 Liters and mols/L = M.

1. 👍 0
2. 👎 0
2. Thanks!!!

1. 👍 0
2. 👎 0
posted by Renee
3. actually when you calculate the equilibrium concentrations of each using the 0.010 L you find that the concentration of KSCN is the limiting reagent. so [FeSCN]^2 = mols KSCN/0.010L

1. 👍 0
2. 👎 0
posted by Abi
4. actually if you read the previous post again Abi. you'll realize it says the same thing! ;]

1. 👍 0
2. 👎 0
posted by leanne

## Similar Questions

1. ### Chem

There are three questions in particular that I am having problems with. Here they are 1. A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration

asked by Mark on January 19, 2009
2. ### Chemistry

A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard solution is assumed to be__?__M

asked by UN on June 28, 2008
3. ### equilibrium concentration

A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard solution is assumed to be ? M. Wouldn't that

asked by Christine on April 4, 2007
4. ### chemistry

A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard solution is assumed to be ____ M.

asked by Gloria on April 10, 2008
5. ### chemistry

A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard solution is assumed to be ?M.

asked by thuy on February 22, 2008
6. ### Chemistry

A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard solution is assumed to be M. What permits

asked by Neil on June 20, 2011
7. ### chemistry

The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN–

asked by thuy on February 22, 2008
8. ### chemistry

The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN¡V

asked by Gloria on April 10, 2008
9. ### chemistry

The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN–

asked by Amy on April 8, 2008
10. ### chem

The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN–

asked by anonymous on April 10, 2008

More Similar Questions