Thursday
April 17, 2014

Homework Help: chemistry

Posted by alex on Monday, April 22, 2013 at 6:04am.

Calculate the weight (in mg) of borax Na2B4O7.10H20 required to react with 25.0 mL if 0.100 M HCI
No. moles HCl consumed = __________ moles
No. moles borax required = __________ moles
Molar mass of borax = __________ g mol-1
(Na2B4O7.10H2O)
Weight borax required = __________ g
= __________ mg




My calculations:
2 HCl + Na2B4O7.10 H2O → H2B4O7 + 2 NaCl + 10 H2O
Number of moles = Volume in liters * Molarity = 0.025 * 0.1 = 0.0025
The ratio of HCl to Na2B4O7.10 H2O is 2 to 1
No. of moles borax required = * 0.0025 = 0.00125

Molar mass of borax = 2 * 23 + 4 * 10.8 + 7 * 16 + 10 *18 = 381.2 grams
Mass of borax = 0.00125 * 381.2
Weight borax required = 0.00125 * 381.2 * 9.8

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Chemistry - a chemist needs to order Na2B4O7. One supplier offers it in an ...
chemistry - The phosphorus in a completely dried fertilizer sample weighing 0....
chemistry - Solid borax dissolves in water according to the equation: Na2B4O7 ...
Chemistry Lab - A student who is performing this experiment pours an 8.50mL ...
Chemistry - If 1.88 g of copper(II) chloride dihydrate is reduced by Mg(s), ...
Chemistry - A reference solution is to be prepared with 5 PPM parabenzopyrene (...
Chemistry - How many mg of Ca^2+ are in one mEq? What I did was mg = mEq x mol ...
chemistry - calculate the theoretical weight of sodium borohydride need to ...
Chemistry - What volume in mL of .100 M NaOH would be required to titrate a 297 ...
Chemistry - Find the number of mg Na2co3 FW = 106g/mol required to prepare 500ml...

Search
Members