please i need the answer within five minutes


label Chemistry
account_circle Unassigned
schedule 1 Day
account_balance_wallet $5

A 118-mg sample of Na2CO3 is dissolved in H2O to give 2.30L of solution. 

What is the concentration of Na+ in parts per million (ppm)?What is the final molarity when 40.00 mL of a 0.803-M HClO4 solution is diluted to 660.00 mL?
Nov 18th, 2017

The molar mass of Na2CO3=23x2+12+16x3=106 g/mol

So the molar of Na2CO3=118x10-3/106=1.11x10-3 mol

1mol Na2CO3 will produce 2mol Na+ in water, So 1.11x10-3 mol Na2CO3 will produce 2.22x10-3 mol Na+ in water.

2.22x10-3 mol Na+=2.22x10-3x23 g Na+=5.11x10-2g Na+

Assuming the density of the solution is the same as the density of water,

2.30L solution=2.30x1000g/L=2.30x10 3 g solution

Therefore the concentration of Na+= 5.11x10-2/2.30x10 3=2.22x10-5=22.2x10-6=22.2 ppm


The molar of HClO4=0.803x40x10-3=32.12x10-3 mol

So the final molarity of HClO4=32.12x10-3 mol/660.00x10-3 L=0.0487 mol/L=0.0487 M

Dec 11th, 2014

Studypool's Notebank makes it easy to buy and sell old notes, study guides, reviews, etc.
Click to visit
The Notebank
...
Nov 18th, 2017
...
Nov 18th, 2017
Nov 19th, 2017
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer