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Tue 21 Jun, 2005 04:19 pm
A mixture is prepared by adding 25 mL of 0.185 M Na3PO4 to 34 mL of 0.140 M Ca(NO3)2
a) what mass of Ca3(PO4)2 will be formed?
b) what will be the concentrations of ecah of the ions in the mixture after reaction?
thanks in advance
First you must complete the reaction
2Na3PO4+3Ca(NO3)2->Ca3(PO4)2+6NaNO3
The determine the quantity of reactants (the left)
25ml*0.185moles/1000ml Na3PO4 (0.004625 mole)
34ml*0.140moles/1000ml Ca(NO3)2 ( 0.00476 mole)
Now determine the limiting reactant [Looks like Ca(NO3)2]
so (0.00476/3 (0.001587) moles of Ca3(PO4)2 and 6*0.001587 (0.00952) moles of NaNO3 will be formed, and 0.004625-0.00476*2/3 (0.001452) moles of Na3PO4 will be left.
And what is the total volume? its 59 (25+34)ml, right. And how many liters is this? Its 59/1000 (0.059 liter right?)
So the molar concentrations after reaction are
0.001587/0.059 M Ca3(PO4)2
0.00952/0.059 M NaNO3
and
0.001452/0.059 M Na3PO4
Right
But if I were you I'd check my arithmetic--
Rap
raprap wrote:First you must complete the reaction
2Na3PO4+3Ca(NO3)2->Ca3(PO4)2+6NaNO3
The determine the quantity of reactants (the left)
25ml*0.185moles/1000ml Na3PO4 (0.004625 mole)
34ml*0.140moles/1000ml Ca(NO3)2 ( 0.00476 mole)
Now determine the limiting reactant [Looks like Ca(NO3)2]
so (0.00476/3 (0.001587) moles of Ca3(PO4)2 and 6*0.001587 (0.00952) moles of NaNO3 will be formed, and 0.004625-0.00476*2/3 (0.001452) moles of Na3PO4 will be left.
And what is the total volume? its 59 (25+34)ml, right. And how many liters is this? Its 59/1000 (0.059 liter right?)
So the molar concentrations after reaction are
0.001587/0.059 M Ca3(PO4)2
0.00952/0.059 M NaNO3
and
0.001452/0.059 M Na3PO4
Right
But if I were you I'd check my arithmetic--
Rap
thank you for your reply. not the first time you've helped me out here. pardon me for not having stated my question clearly. I actually wanted to find the concentration of each ion after the reaction.
thanks