The patient needs 1000 ml of 5% (w/v) glucose solution
i.e 1000 ml x 5 g/ 100 ml
where the stock solution is 55% (w/v) = 55 g / 100 ml
So, 1000 ml x 5 g / 100 ml = V (ml) x 55 g / 100 ml
V = 1000 x (5 / 100) / (55 / 100) = 5000 / 55 = 90.9 ml
∴ the patient needs 90.9 ml of 55% (w/v) glucose solution
Answer:
This is an example of chemical change because the Kool aid dissolved and turned the water red
We determine the limiting reactant by using the moles present in the equation and the actual moles.
According to equation, ratio of Fe₂O₃ : Al = 1 : 2
Actual moles of Fe₂O₃ = 187.3 / (56 x 2 + 16 x 3)
= 1.17
Actual moles of Al = 94.51 / 27
= 3.5
Fe₂O₃ is limiting. Fe₂O₃ required:
(moles Al)/2 = 3.5/2 = 1.75
Moles to be added = 1.75 - 1.17
= 0.58
Mass to be added = moles x Mr
= 0.58 x (56 x 2 + 16 x 3)
= 92.8 grams
All are true except the statement that ions are formed by changing the number protons in an atom’s nucleus.
A neutral atom contains the same number of protons (positive charge) and electrons (negative charge).
If there are <em>more electrons than protons</em>, the atom becomes a <em>negative ion</em>.
If there are <em>fewer electrons than protons</em>, the atom becomes a <em>positive ion</em>.
The protons are in the nucleus, where we can’t easily get at them. The <em>electrons are outside the nucleus</em>, so other chemicals can easily get at them and either remove them or add to their number.
<em>Metals</em> have only a few valence electrons, so it is fairly easy to remove them and <em>form positive ions</em>.
Mass spectrometry was discovered by Francis Aston, a British Physicist, in 1919. This involves separating mixtures of substances into their components and transforming them into beams of particles and subsequently, bending them with the use of electricity and magnetism to come up with a spectrum that is inherently unique for every individual atoms for easy identification.
