Need help calculating percent composition

Click For Summary

Discussion Overview

The discussion revolves around calculating the percent composition of casein and lactose in nonfat milk. Participants explore methods for determining these values based on experimental results and the need for density information.

Discussion Character

  • Homework-related, Technical explanation

Main Points Raised

  • One participant seeks assistance in calculating the percent composition of casein and lactose, noting the quantities obtained from an experiment.
  • Another participant suggests that knowing the weight of the 50ml of milk would be necessary for calculating percent composition by weight.
  • A participant expresses concern about not having weighed the milk, as the procedure did not specify this requirement.
  • One comment critiques the use of % w/v as a measure, labeling it as "stupid and rather faulty," yet acknowledges it as a fallback option.
  • A later reply indicates that the original poster resolved their issue by obtaining the density of milk from a classmate's different procedure, which allowed them to proceed with the calculations.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best method for calculating percent composition, as there are differing opinions on the necessity of weighing the milk and the appropriateness of using % w/v.

Contextual Notes

The discussion highlights limitations related to the lack of density information and the absence of weighing the milk, which are critical for accurate calculations.

babbagee
Messages
71
Reaction score
0
Hello,

I need some help calculating the pecent composition of casien and lactose in milk. I started out with 50ml of nonfat milk, at the end of the experiment I got 1.599g casien and 1.610g of lactose. My idea was to convert these values into ml using density but I could not find the densities. Can someone lead me in the right direction.
 
Chemistry news on Phys.org
Rajvirnijjar said:
Hello,

I need some help calculating the pecent composition of casien and lactose in milk. I started out with 50ml of nonfat milk, at the end of the experiment I got 1.599g casien and 1.610g of lactose. My idea was to convert these values into ml using density but I could not find the densities. Can someone lead me in the right direction.

if you are doing % composition by weight, then what is the weight of 50ml of milk? that would be all that you would need.
 
Thats the problem, I just used 50ml of milk, i did not weigh it. The procedure I was following just said to use 50ml of milk, it did not say anything about weighing it.
 
You may give your results as % w/v - stupid and rather faulty units, but better then nothing.
 
I actually figure it out. The procedure I was using did not give the density of milk, but one of my classmates had a different version of the procedure which gave the density. That was the only reason i was having this problem. I did not know the density. Thanks for your guys help
 

Similar threads

Calculate the density of composite materials
  • · Replies 5 ·
Replies
5
Views
3K
Given percent composition, find mass per litre of solution
  • · Replies 6 ·
Replies
6
Views
3K
Determing the mass percent of chloride from a mixture of NaCl and KCl salts
  • · Replies 5 ·
Replies
5
Views
7K
Undergrad What percent of the universe is outside of galaxies?
  • · Replies 20 ·
Replies
20
Views
3K
Simplified Calculations for Nylon66 Composite Material Supporting Heavy Loads
  • · Replies 3 ·
Replies
3
Views
2K
How to Calculate Atom/B-cm Values for Nuclear Fuel Composition?
  • · Replies 6 ·
Replies
6
Views
3K
High School Sig figs/certainty in percent error calculation
  • · Replies 8 ·
Replies
8
Views
6K
Redox titration and mass percent composition calculations.
  • · Replies 9 ·
Replies
9
Views
17K
Calculating Lactose Intake with Lactaid Caplets
  • · Replies 2 ·
Replies
2
Views
7K
Chemistry What is the percentage of KClO3 in a mixture after removing oxygen?
  • · Replies 12 ·
Replies
12
Views
3K