Answer:
-7.34 kilo Joules is the change in enthaply when 20.0 grams of nitrogen triiodide decomposes.
Explanation:
Mass of nitrogen triiodide = 20.0 g
Moles of nitrogen triiodide = 

According to reaction, 2 moles of nitrogen triiodide gives 290.0 kilo Joules of heat on decomposition ,then 0.05063 moles of nitrogen triiodide will give :

-7.34 kilo Joules is the change in enthaply when 20.0 grams of nitrogen triiodide decomposes.
Vertical Column is a group
Horizontal is Period
Aliki earth metals is a group
Lithium- Neon is both
Based on electrons are both
Number of electron shells is both
Answer:
Explanation:
From the periodic table, the element designated as Sn is tin. Sn is derieved from a latin name of the metal called Stanum
Selenium Se is a group 6 element. It belongs to the same group with oxygen, sulfur and tellurium. This substance has an atomic weight of 78.96g/mol
Oxygen is a group 6 element with an atomic mass of 16. The atomic mass is the number of protons in the nucleus of this atom.
Answer:
0.188mol
Explanation:
Using the formula;
mole = mass/molar mass
Molar mass of hypomanganous acid. (H3MnO4) = 1(3) + 55 + 16(4)
= 3 + 55 + 64
= 122g/mol
According to this question, there are 22.912g of H3MnO4
mole = 22.912g ÷ 122g/mol
mole = 0.188mol