Posted by **Sai** on Monday, March 29, 2010 at 5:38pm.

Just..... don't get it

A column packing for chromatography consists of a mixture of two types of particles. Assume that the particles in the batch being sampled are spherical with a radius of 0.5 mm. 36% of the particles appeared to be pink and are known to have a polymeric stationary phase attached. The average density of the mixture is 0.288 g cm-3. If 5.3126(+/-)0.0003 g of the sample is weighed out, calculate,

(i) the number of particles in the sample

(ii) the % standard deviation in sampling the fraction of pink particles from this mass of the sample.

(iii) Which contributes the larger uncertainty to the procedure - weighing out the sample or the random error associated with sampling from the two-component mixture? Justify your answer with a calculation.

(iv) Assume that the % standard deviation in sampling is 8%. How many replicate samples of this packing material need to be taken so that there is 95% confidence that the mean is known to within „b6% of the true mean.

plz helppp

## Answer this Question

## Related Questions

- statistics - A column packing for chromatography consists of a mixture of two ...
- chemistry - This is super confusing complex brain killing A column packing for ...
- chemistry - consider a random mixture of two particles,diamond and SiC.Assume ...
- chemistry - Earth's population is about 6.5 billion. Suppose that every person ...
- chemistry - Earth's population is about 6.5 billion. Suppose that every person ...
- column chromatography - A student loaded a mixture, dissolved in 1cm3 of ...
- chemistry - Earth's population is about 6.5 billion. Suppose that every person ...
- chemistry - Earth's population is about 6.5 billion. Suppose that every person ...
- science - 1.which two particles are found in an atoms nucleus? 2. which two ...
- physics - Spherical particles of a protein of density 1.4 g/cm3 are shaken up in...

More Related Questions