Alchemists advanced the tools and procedures for working with chemicals. Alchemists also developed methods for sorting out mixtures and cleansing chemicals. They designed equipment that is still in use today including beakers, flasks, tongs, funnels, and the mortar and pestle. Also, Alchemists backed to an unbelievable variety of what would later be acquainted as chemical industries: basic metallurgy, metalworking, the invention of inks, dyes, paints, and cosmetics, leather-tanning, and the preparation of extracts and liquors.
Answer:
Explanation:
H3PO4(aq) + 3NaOH(aq) → Na3PO4(aq) + 3H2O(l)
mole of NaOH = 23.6 * 10 ⁻³L * 0.2M
= 0.00472mole
let x be the no of mole of H3PO4 required of 0.00472mole of NaOH
3 mole of NaOH required ------- 1 mole of H3PO4
0.00472mole of NaOH ----------x
cross multiply
3x = 0.0472
x = 0.00157mole
[H3PO4] = mole of H3PO4 / Vol. of H3PO4
= 0.00157mole / (10*10⁻³l)
= 0.157M
<h3>The concentration of unknown phosphoric acid is 0.157M</h3>
Answer:
The nuclear charge increases, but the number of inner shielding electrons stays the same.
Explanation:
Their shielding does not change, so the effective nuclear charge — the charge felt by a valence electron — increases.
The valence electrons are pulled closer to the nucleus, decreasing the atomic radius.
For example, consider the elements of Period 3.
The number of protons increases as you go from one element to the next, but the number of inner electrons is constant.
