Answer:
The law of definite proportions
Explanation:
The law of definite proportions states that atoms combine in a molecule in a specific molar ratio or specific stoichiometry. For example, it's proved that regardless of the quantity we take, two hydrogen atoms always combine with one oxygen atom to form a water molecule.
Similarly, ionic substances follow the same pattern. Since the net charge of ionic salts should be equal to 0 and each element has a definite number of valence electrons in its shell all the time, the ions combine in a way, so that cations balance the charge of anions.
Essentially, the law of definite proportions is applicable and will be applicable in the future, since we know that each element has a fixed number of valence electrons in its ground state.
The boiling points of alkanes increases with increasing number of carbons. This is because the intermolecular attractive forces, although individually weak, become cumulatively more significant as the number of atoms and electrons in the molecule increases.
So therefore your answer choice will increase. (B)
Answer:
1.263 moles of HF
Explanation:
The balance chemical equation for given single replacement reaction is;
Sn + 2 HF → SnF₂ + H₂
Step 1: <u>Calculate Moles of Tin as;</u>
As we know,
Moles = Mass / A.Mass ----- (1)
Where;
Mass of Tin = 75.0 g
A.Mass of Tin = 118.71 g/mol
Putting values in eq. 1;
Moles = 75.0 g / 118.71 g/mol
Moles = 0.6318 moles of Sn
Step 2: <u>Find out moles of Hydrogen Fluoride as;</u>
According to balance chemical equation,
1 mole of Sn reacted with = 2 moles of HF
So,
0.6318 moles of Sn will react with = X moles of HF
Solving for X,
X = 0.6318 mol × 2 mol / 1 mol
X = 1.263 moles of HF
Answer:
A perfect mold of a dinosaur bone
