Example: serum containing na gave a signal of 4.27 mv in an atomic emission analysis. then, 5 ml of 2.08 m nacl were added to 95.0 ml of serum. the spiked serum gave a signal of 7.98 mv. find the original concentration of nat in serum.

Explanation:

It is known that,

       No. of moles = Concentration × volume

As 5 ml of 2.08 M NaCl NaS added to 95 ml of serum then,

        Total volume = (95 + 5) ml = 100 ml

Therefore, total moles of = (5 × 2.08) + (95 × x)

where,      x =  concentration of in original serum

Hence, signal obtained for this NaS = 7.8 mV

Let us assume same volume, that is, 100 ml Serum then will be (100 × x) mol.

Signal obtained for this is 4.27 mV.

Now, the ratio of signal is equal to the ratio of mole.

So,  

                           x = 0.113

Thus, we can conclude that original concentration of in Serum is 0.113.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

2b2t

explanation:

2b2t