Answer:
C. Hair dryer
Explanation:
Alternating Current
The other kind of electricity is called alternating current, or AC. Power plants produce this
type of electricity. It is carried by large power lines from the plant to your home. When you
plug a TV, a lamp, or a hair dryer into the wall socket, you are using this type of electricity.
Answer: Option (A) is the correct answer.
Explanation:
Condensation is defined as the process in which vapors or gaseous phase changes into liquid phase.
Freezing is the process in which liquid phase changes into solid phase.
Evaporation is the process in which liquid phase changes into vapors or gaseous phase.
Melting is the process in which solid phase changes into liquid phase.
Therefore, we can conclude that names for given phase changes A and B is that A is condensation and B is freezing.
Answer:
1. C + O₂ → CO₂
2. C + CO₂ → 2 CO
3. Fe₂O₃ + 3 CO → 2 Fe + 3 CO₂
Answer:
the physical and chemical properties of the products are different from the reactants
Explanation:
A chemical reaction involves the chemical combination of two or more elements/compounds called Reactants to give one or more different elements/compounds called Products. A chemical reaction occurs in such a way that the atoms of the reactants are restructured to form product(s) that is/are entirely different from the reactants.
In a chemical reaction, the physical and chemical properties of the products differ from that of the reactants since different chemical compounds/elements are formed as products. The physical properties of a substance, which include colour, melting and boiling point etc. will differ in the reactants and products formed. Also, the chemical structure and identity of the reactants will be changed to give rise to a different chemical property in the products.
Answer:
0.259 kJ/mol ≅ 0.26 kJ/mol.
Explanation:
- To solve this problem, we can use the relation:
<em>Q = m.c.ΔT,</em>
where, Q is the amount of heat absorbed by ice (Q = ??? J).
m is the mass of the ice (m = 100.0 g).
c is the specific heat of water (c of ice = 4.186 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 21.56°C - 25.0°C = -3.44°C).
<em>∵ Q = m.c.ΔT</em>
∴ Q = (100.0 g)(4.186 J/g.°C)(-3.44°C) = -1440 J = -1.44 kJ.
<em>∵ ΔH = Q/n</em>
n = mass/molar mass = (100.0 g)/(18.0 g/mol) = 5.556 mol.
∴ ΔH = (-1.44 kJ)/(5.556 mol) = 0.259 kJ/mol ≅ 0.26 kJ/mol.
