Answer:
% composition O = 19.9%
% composition Cu = 80.1%
Explanation:
Given data:
Total mass of compound = 3.12 g
Mass of copper = 2.50 g
Mass of oxygen = 3.12 - 2.50 = 0.62 g
% composition = ?
Solution:
Formula:
<em>% composition = ( mass of element/ total mass)×100</em>
% composition Cu = (2.50 g / 3.12 g)×100
% composition Cu = 0.80 ×100
% composition Cu = 80.1%
For oxygen:
<em>% composition = ( mass of element/ total mass)×100</em>
% composition O = (0.62 g / 3.12 g)×100
% composition O = 0.199 ×100
% composition O = 19.9%
Answer:
See below
Explanation:
propane mole weight = 44 gm / mole
100 gm / 44 gm / mole = 2.27 moles
From the equation, 5 times as many moles of OXYGEN (O2)are required
= 11.36 moles of oxygen
at <u>STP</u> this is 254.55 liters of O2 (because 22.4 L = one mole) and
Using oxygen as 21 percent of air means that
.21 x = 254.55 = x = <u>1212.12 liters of air required </u>
Answer:
( °F − 32) × 5/9 = °C
Explanation:
Also there is a mental calculation to convert from Fahrenheit to Celsius. The ratio 5/9 is approximately equal 0.55555….
Subtract 32º to adapt the equivalent in the Fahrenheit scale.
Divide the degrees Celsius by 2 (multiply by 0.5).
Take 1/10 of this number (0.5 * 1/10 = 0.05) and add it to the number obtained previously.
Example: Convert 98.6º F to Centigrade.
98.6 - 32 = 66.6
66.6 * 1/2 = 33.3
33.3 * 1/10 = 3.3
33.3 + 3.3 = 36.6 which is an approximation in degrees Centigrade
The molar mass of naphthalene is calculated as follows,
10 x (12.01 g/ mol) + 8 x (1.01 g/mol) = 128.12 g/mol
Divide the given mass by the molar mass to determine the number of moles of naphthalene present in the ball.
n = 1.52 g / 128.12 g/mol = 0.01186 mole
Multiply the number of moles to number of moles per mole.
(0.01186 mol) x (6.022 x10^23 molecules / mole) = 7.14 x 10^21 molecules
DR is the correct answer
hope this helps
