Answer:
Water boils - physical change
Salt dissolves in water- chemical change
Milk turns sour- chemical change
metal rusts - chemical change
Explanation:
A chemical change refers to changes that are irreversible and the process involves the evolution of heat along with the formation of a new substance, examples include;Salt dissolves in water, Milk turns sour, metal rusts etc
The boiling of water is a physical change. The water can be cooled and the vapour condensed,hence, the boiling of water is a physical change.
Physical changes are easily reversible and no new substance is formed.
Answer:
0.6 moles NH₃
Explanation:
The reaction that takes place is:
First we <u>determine the limiting reactant</u>:
- 0.35 mol N₂ would react completely with (3*0.35) 1.05 moles of H₂. There are not as many H₂ moles, so H₂ is the limiting reactant.
Then we <u>convert H₂ moles (the limiting reactant) to NH₃ moles</u>, keeping in mind the <em>stoichiometry of the reaction</em>:
- 0.90 mol H₂ *
= 0.6 moles NH₃
Answer:
Ionic character
A. PF₃ > PBr₃ > PCl₃
B. BF₃ > CF₄ > NF₃
C. TeF₄ > BrF₃ > SeF₄
Explanation:
The most electronegative element is fluorine, followed chlorine, phosphorous nitrogen etc.
- Atoms with high electronegativity tend to form negative ions.
- Ionic compounds formed between elements with high electronegativity difference.
- % ionic character is directly proportional to electronegativity difference.
- According to Pauling Scale E.n for F(4.0), O(3.5), N(3.0), C(2.5), B(2.0), P(2.19), Se(2.55) , Te (2.1), Cl(3.16) and Br(2.96)
- ΔE.N (Electronegativity difference) between( P and F = 4 - 2.19 = 1.81), (P and Br = 2.96 - 2.19 = 0.77) , (P and Cl = 3.16 - 2.96 = 0.2 )
- ΔE.N (Electronegativity difference) between( N and F = 4 - 3 = 1), (B and F = 4 - 2 = 2) , (C and F = 4 - 2.5 = 1.5 )
- ΔE.N (Electronegativity difference) between( Se and F = 4 - 2.55 = 1.45), (F and Te = 4 - 2.1 = 1.9) , (F and Br = 4 - 2.19 = 1.81 )
Answer: iodine 131 iodine 132 isotopes
Explanation:
