Answer:the answer is moles
Explanation: joules are measurements of energy, and moles Joules
Answer:
the answer will be 2,280 cm>2
An imaginary line joining a planet and the sun sweeps out an equal area of space in equal amounts of time. Thus, the speed of the planet increases as it nears the sun and decreases as it recedes from the sun.
95.6 cal
are needed.
Explanation:
Use the following equation:
q
=
m
c
Δ
T
,
where:
q
is heat energy,
m
is mass,
c
is specific heat capacity, and
Δ
T
is the change in temperature.
Δ
T
=
T
final
−
T
initial
Known
m
=
125 g
c
Pb
=
0.130
J
g
⋅
∘
C
T
initial
=
17.5
∘
C
T
final
=
42.1
∘
C
Δ
T
=
42.1
∘
C
−
17.5
∘
C
=
24.6
∘
C
Unknown
q
Solution
Plug the known values into the equation and solve.
q
=
(
125
g
)
×
(
0.130
J
g
⋅
∘
C
)
×
(
24.6
∘
C
)
=
400. J
(rounded to three significant figures)
Convert Joules to calories
1 J
=
0.2389 cal
to four significant figures.
400
.
J
×
0.2389
cal
1
J
=
95.6 cal
(rounded to three significant figures)
95.6 cal
are needed.
The correct option is B.
Phenophtalein is an indicator that is usually used in acid base titration experiments. Indicators are substances that undergo distinct, observable changes when the pH of their solutions change. Indicators exhibit changing of colors depending on the pH of the solution in which they are found. They are usually weak bases and acid which are capable of partial dissociation and formation of ions when dissolved in water. There are different types of indicator and phenophtalein is one of them. Phenophtalein is colorless in acidic solution and pink in basic solutions.
