How to calculate percent error of a melting point range? Melting Point Average 122.5°C - 128°C
Literature Melting Point 121°C - 123°C
% Error (melting point)

3.9%

Explanation:

Exact melting point = 123°C

Measured melting point = 128°C

% error; |measured - exact|/exact × 100

% error = |123 -128|/128 × 100

%error = 3.9%

Percentage error in temperature measurement = 3.9 %

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.