Answer:
Both require time, but velocity requires displacement and speed requires distance
Explanation:
For calculating speed we require time and distance because speed is defined as the distance per unit time and as speed is a scalar quantity it does not have any direction
But for calculating the velocity we require time as well as displacement because velocity is defined as the displacement per unit time and as velocity is a vector quantity it has direction
Displacement is the shortest distance between the initial position and the final position and it has a specified direction as well
Answer:
81°C.
Explanation:
To solve this problem, we can use the relation:
<em>Q = m.c.ΔT,</em>
where, Q is the amount of heat released from water (Q = - 1200 J).
m is the mass of the water (m = 20.0 g).
c is the specific heat capacity of water (c of water = 4.186 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = final T - 95.0°C).
∵ Q = m.c.ΔT
∴ (- 1200 J) = (20.0 g)(4.186 J/g.°C)(final T - 95.0°C ).
(- 1200 J) = 83.72 final T - 7953.
∴ final T = (- 1200 J + 7953)/83.72 = 80.67°C ≅ 81.0°C.
<em>So, the right choice is: 81°C.</em>
Answer:
ΔH = 125.94kJ
Explanation:
It is possible to make algebraic sum of reactions to obtain ΔH of reactions (Hess's law). In the problem:
1. 2W(s) + 3O2(g) → 2WO3(s) ΔH = -1685.4 kJ
2. 2H2(g) + O2(g) → 2H2O(g) ΔH = -477.84 kJ
-1/2 (1):
WO3(s) → W(s) + 3/2O2(g) ΔH = 842.7kJ
3/2 (2):
3H2(g) + 3/2O2(g) → 3H2O(g) ΔH = -716.76kJ
The sum of last both reactions:
WO3(s) + 3H2(g) → W(s) + 3H2O(g)
ΔH = 842.7kJ -716.76kJ
<h3>ΔH = 125.94kJ </h3>
Option D
A precipitate is the term for a solid that forms when two solutions are mixed
<u>Explanation:</u>
A solid set from a couple of solutions is termed a precipitate. A precipitate is an unsolved solid that makes when a pair of solutions are fused and react chemically. Unsolvable means that the solid will not melt. When the effect transpires in a liquid solution, the solid developed is denominated the 'precipitate'.
The substance that generates the solid to make is termed the 'precipitant'. Seldom the development of a precipitate symbolizes the existence of a chemical reaction. Precipitation may additionally transpire immediately from a supersaturated solution.
Answer:
Weathering is the breakdown of rock by natural forces and chemical changes
Explanation:
The air and water (rain) are natural forces that breaks down rocks
