Soil Science Project Help - Experiment

[SarahBuck]

Hey,

I am to complete a project that involves doing an experiment
'to determine the impact of each additive, the effects on samples of a
garden soil of adding 20% by mass of (a) sand, (b) potting compost, and © clay on the rate of drainage of soil'.

My question is:
does one add the additive that would equates to 20% of the mass of the garden soil i.e. adding 20g of sand to 100g of garden soil
or
does remove 20% of the garden soil and replace it with the additive i.e. 20g of sand mixed with 80g of garden soil.


Thanks in advance for any help!

[studiot]

Hey,

 

I am to complete a project that involves doing an experiment

'to determine the impact of each additive, the effects on samples of a

garden soil of adding 20% by mass of (a) sand, (b) potting compost, and © clay on the rate of drainage of soil'.

 

My question is:

does one add the additive that would equates to 20% of the mass of the garden soil i.e. adding 20g of sand to 100g of garden soil

or

does remove 20% of the garden soil and replace it with the additive i.e. 20g of sand mixed with 80g of garden soil.

 

 

Thanks in advance for any help!

 

Hello Sarah and welcome to ScienceForums.

 

This is a good and perceptive question and you should confirm the actual meaning with your tutors as the wording is a bit lax. +1 for spotting it.

 

Normal practice in the scientific world for mixtures, solutions etc is to refer to % by mass ( or volume) of the mixture, not of any of the consituents so I would expect they meant your second answer.

 

However strictly if they simply said add 20% by mass then your first answer is correct.

 

The technical word for adding 20% is to add 20% to the admixture.

 

They really need the word mixture in there somewhere to make it plain.

Edited January 13, 2017 by studiot

[SarahBuck]

Hey,

I am to complete a project that involves doing an experiment
'to determine the impact of each additive, the effects on samples of a
garden soil of adding 20% by mass of (a) sand, (b) potting compost, and © clay on the rate of drainage of soil'.

The working of the the title is whats confusing me. My question is:

does one add the additive that would equates to 20% of the mass of the garden soil i.e. adding 20g of sand to 100g of garden soil
or
does remove 20% of the garden soil and replace it with the additive i.e. 20g of sand mixed with 80g of garden soil.


Thanks in advance for any help!

[StringJunky]

 

Hey,

 

I am to complete a project that involves doing an experiment

'to determine the impact of each additive, the effects on samples of a

garden soil of adding 20% by mass of (a) sand, (b) potting compost, and © clay on the rate of drainage of soil'.

 

The working of the the title is whats confusing me. My question is:

 

does one add the additive that would equates to 20% of the mass of the garden soil i.e. adding 20g of sand to 100g of garden soil

or

does remove 20% of the garden soil and replace it with the additive i.e. 20g of sand mixed with 80g of garden soil.

 

 

Thanks in advance for any help!

 

The first one. I think, if it was the latter, they would say "Replace or substitute 20% by mass....."

Edited January 14, 2017 by StringJunky