Explanation:
Molar mass
The mass present in one mole of a specific species .
The molar mass of a compound , can easily be calculated as the sum of the all the individual atom multiplied by the number of total atoms .
(a) P₄
Molar mass of of the atoms are -
Phosphorous , P = 31 g/mol
Molecular mass of P₄ = ( 4 * 31 ) = 124 g/mol .
(b) H₂O
Molar mass of of the atoms are -
Hydrogen , H = 1 g/mol
oxygen , O = 16 g/mol.
Molecular mass of H₂O = ( 2 * 1 ) + ( 1 * 16 ) = 18 g/mol
(c) Ca(NO₃)₂
Molar mass of of the atoms are -
calcium , Ca = 40 g/mol
nitrogen, N = 14 g/mol
oxygen , O = 16 g/mol.
Molecular mass of Ca(NO₃)₂ = ( 1 * 40 ) + ( 2 * 14 ) + ( 6 * 16 ) = 164 g/mol.
(d)CH₃CO₂H (acetic acid)
Molar mass of of the atoms are -
Carbon , C = 12 g/mol.
oxygen , O = 16 g/mol.
Hydrogen , H = 1 g/mol
Molecular mass of CH₃CO₂H =( 2 * 12 ) + (2 * 16 ) + (4 * 1 ) = 60 g/mol.
(e) C₁₂H₂₂O₁₁ (sucrose, cane sugar).
Molar mass of of the atoms are -
Carbon , C = 12 g/mol.
oxygen , O = 16 g/mol.
Hydrogen , H = 1 g/mol
Molecular mass of C₁₂H₂₂O₁₁ = (12 * 12 ) + ( 22 * 1 ) + ( 11 * 16 ) = 342 g/mol.
Answer:
Value of coefficient of kinetic friction is 0.26 .
Explanation:
Given:
Mass of wooden crate, m = 12.5 kg.
Horizontal force to keep the block moving with constant velocity, F = 32.0 N.
Since, the block is moving with constant velocity.
So, net force experience by it is zero.
Therefore, fore of friction is equal to applied force.
Now, force of friction , 
( here 
is coefficient of kinetic friction and N is normal force)
Therefore, 
Now, both forces are equal.
The value of coefficient of kinetic friction is 0.26 .
Hence, it is the required solution.
The correct answer is: [C]: "Br" {"bromine"} .
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Average atomic mass of an element is a sum of the product of the isotope mass and its relative abundance.
For example: Chlorine has 2 isotopes with the following abundances
Cl(35): Atomic mass = 34.9688 amu; Abundance = 75.78%
Cl(37): Atomic mass = 36.9659 amu; Abundance = 24.22 %
Average atomic mass of Cl = 34.9688(0.7578) + 36.9659(0.2422) =
= 26.4993 + 8.9531 = 35.4524 amu
Thus, the term “ average atomic mass “ is a <u>weighted</u> average so it is calculated differently from a normal average
Answer:
Percent yield of PI3 = 95.4%
Explanation:
This is the reaction:
2P (s) + 3I2 (g) > 2PI3 (g)
Let's determine the moles of iodine that has reacted.
58.6 g / 253.8 g/mol = 0.231 mol
Ratio is 3:2. Let's make a rule of three to state the moles produced at 100 % yield reaction.
3 moles of I2 react to make 2 moles of PI3
0.231 moles of I2 would make (0.231 .2) / 3 = 0.154 moles of PI3
As we have produced 0.147 moles let's determine the percent yield.
(Yield produced / Theoretical yield) . 100 > (0.147 / 0.154) . 100 = 95.4%
