Answer:
The mass of board is 1.52 g.
Explanation:
Given data:
Density of wood = 0.487 g/cm³
Length of board = 3.21 cm
Width of board = 12.2 cm
Height of board = 0.80 mm (0.80/10=0.08 cm)
Mass of board = ?
Solution:
We know that density of an object is equal to the mass of substance divided by its volume. So we can calculate the mass from density formula.
Formula:
D = m/v
d = density
m = mass
v = volume
Now we will calculate the volume first.
V = length × width × height
V = 3.21 cm × 12.2 cm × 0.08 cm
V = 3.13cm³
Now we will calculate the mass.
D = m/v
0.487 g/cm³ = m/ 3.13 cm³
m = 0.487 g/cm³ × 3.13 cm³
m = 1.52 g
The mass of board is 1.52 g.
Answer:
The final temperature of the iron is:- 38.0 °C
Explanation:
The initial temperature = 24.7 °C
Let Final temperature = T °C
Using,
Q = m C ×ΔT
Where,
Q is the heat absorbed by the iron = 85.7 J
C gas is the specific heat of the iron = 0.45 J/g °C
m is the mass of iron = 14.3 g
ΔT is the change in temperature. ( T - 24.7 ) °C
Applying the values as:
<u>Q = m C ×ΔT </u>
85.7 J = 14.3 g × 0.45 J/g °C × ( T - 24.7 ) °C
Solving for T, we get that:-
T = 38.0 °C
<u>The final temperature of the iron is:- 38.0 °C</u>
Explanation:
An observation is defined as the process which explains how it is happening (qualitative) and and quantitatively able to measure something about the process.
A law is defined as a verified statement that will remain true under the mentioned circumstances as it is based on the past observations that are carefully tested.
A theory is defined as the explanation of an aspect of natural world that can be tested, modified or rejected as a result of further experiments.
Hence, the given statements are classified as follows.
(a) All matter is made of tiny, indestructible particles called atoms - Theory
(b) When iron rusts in a closed container, the mass of the container and its contents does not change - Observation
(c) In chemical reactions, matter is neither created nor destroyed - Law
(d) When a match burns, heat is evolve - Observation
Let's see
- ∆S refers to the total change in entropy of system.
Graphite was in solid state and oxygen was in gaseous state.
When they synthesized they converted to gaseous state
- So randomness of particles increases
- So entropy also increases
∆S=+ve
