Answer:
Explanation:
NaCl does not contain molecules
27.6 - 22.3 = 5.3; you simply subtract the old density from the new density.
Döbereiner grouped the known elements into <em>triads</em> (sets of three) so that
• The <em>atomic mass of the middle element</em> was approximately the average of the other two
• The <em>chemical properties of the middle element</em> were between those of the other two
• The <em>physical properties of the middle element</em> were between those of the other two
One example of a triad is Li – Na – K.
(a) Atomic mass of Na = 23.0 u
Average atomic mass of Li and K = (6.9 u + 39.1 u)/2 = 46.0 u/2 = 23.0 u
(b) Li reacts slowly with water. Na reacts rapidly. Potassium reacts violently.
(c) Melting point of Na = 371 °C.
Average melting point of Li and K = (454 °C + 330 °C)/2 = 784 °C/2
= 392 °C
Answer:
0.683 moles of the gas are required
Explanation:
Avogadro's law relates the moles of a gas with its volume. The volume of a gas is directely proportional to its moles when temperature and pressure of the gas remains constant. The law is:
V₁n₂ = V₂n₁
<em>Where V is volume and n are moles of 1, initial state and 2, final state of the gas.</em>
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Computing the values of the problem:
1.50Ln₂ = 5L*0.205mol
n₂ = 0.683 moles of the gas are required
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