Answer:
100g/mol
Explanation:
Given parameters:
Mass of unknown gas = 2g
Volume of gas in flask = 500mL = 0.5dm³
Unknown:
Molar mass of gas = ?
Solution:
Since we know the gas is at STP;
1 mole of substance occupies 22.4dm³ of space at STP
Therefore,
0.5dm³ will have 0.02mole at STP
Now;
Number of moles = 
Molar mass = 
= 
= 100g/mol
Answer:
0.0344 M
Explanation:
- HC₂H₃O₂ (aq) + OH⁻ (aq) --> C₂H₃O₂⁻ (aq) + H₂O (l)
Because one mol of vinegar (acetic acid) reacts with one mol of NaOH, we can use the formula
Where C₁ and V₁ refer to the concentration and volume of vinegar, and C₂ and V₂ to those of NaOH. We're given V₁, C₂ and V₂; so we <em>solve for C₁</em>:
- C₁ = 0.0500 M * 16.7 mL / 25.0 mL
Answer:
C₂H₇F₂P
Explanation:
Given parameters:
Composition by mass:
C = 24%
H = 7%
F = 38%
P = 31%
Unknown:
Empirical formula of compound;
Solution :
The empirical formula is the simplest formula of a compound. To solve for this, follow the process below;
C H F P
% composition
by mass 24 7 38 31
Molar mass 12 1 19 31
Number of
moles 24/12 7/1 38/19 31/31
2 7 2 1
Dividing
by the
smallest 2/1 7/1 2/1 1/1
2 7 2 1
Empirical formula C₂H₇F₂P
The protons in an nucleus of an atom will not change unless a nuclear reaction takes place. The number of protons is equal to the atomic number of the element. For a neutral atom, the number of electrons and protons are equal. When they are unequal, then the atom occurs as an ion. It will has a net charge with it. The ion O²⁻ has a net charge of negative positive 2 because it has 2 more electrons than its protons. Since neutral oxygen has 8 protons, then O²⁻ ion has 8 protons and 10 electrons.
