They have high melting and boiling points and are hard and brittle
There are several ways to give an object potential energy. One can move the object against the force of gravity to increase. One can also stretch an object out or put pressure on it.
Answer:
kf = 1.16 x 10¹⁸
Explanation:
Step 1: [Ni(H₂O)₆]²⁺ + 1en → [Ni(H₂O)₄(en)]²⁺ ΔG°1 = -42.9 kJmol⁻¹
Step 2: [Ni(H₂O)₄(en)]²⁺ + 1en → [Ni(H₂O)₂(en)₂]²⁺ ΔG°2 = -35.8 kJmol⁻¹
Step 3: [Ni(H₂O)₂(en)₂]²⁺ + 1en → [Ni(en)₃]²⁺ ΔG°3 = -24.3 kJmol⁻¹
________________________________________________________
Overall reaction: [Ni(H₂O)₆]²⁺ + 3en → [Ni(en)₃]²⁺ ΔG°r
ΔG°r = ΔG°1 + ΔG°2 + ΔG°3
ΔG°r = -42.9 - 35.8 - 24.3
ΔG°r = -103.0 kJmol⁻¹
ΔG°r = -RTlnKf
-103,000 Jmol⁻¹ = - 8.31 J.K⁻¹mol⁻¹ x 298 K x lnKf
kf = e ^(-103,000/-8.31x298)
kf = e ^41.59
kf = 1.16 x 10¹⁸
Answer : The temperature of liquid is, 369.9 K
Explanation :
The Clausius- Clapeyron equation is :
where,
= vapor pressure of liquid at 373 K = 681 torr
= vapor pressure of liquid at normal boiling point = 760 torr
= temperature of liquid = ?
= normal boiling point of liquid = 373 K
= heat of vaporization = 40.7 kJ/mole = 40700 J/mole
R = universal constant = 8.314 J/K.mole
Now put all the given values in the above formula, we get:
Hence, the temperature of liquid is, 369.9 K
Answer:
D =Average atomic mass = 10.801 amu.
5) True
Explanation:
Abundance of B¹⁰= 19.9%
Abundance of B¹¹ = 80.1%
Atomic mass of B¹⁰ = 10 amu
Atomic mass of B¹¹ = 11 amu
Average atomic mass = ?
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (10×19.9)+(11×80.1) /100
Average atomic mass = 199 + 881.1 / 100
Average atomic mass = 1080.1 / 100
Average atomic mass = 10.801 amu.
2)A chemical reaction is one in which a new elements is created
True
False
Answer:
In chemical reaction new substances are created.
For example:
Photosynthesis:
It is the process in which in the presence of sun light and chlorophyll by using carbon dioxide and water plants produce the oxygen and glucose.
Carbon dioxide + water + energy → glucose + oxygen
water is supplied through the roots, carbon dioxide collected through stomata and sun light is capture by chloroplast.
Chemical equation:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen.
