D) + ΔH and +ΔE
Given this is one of the answer choices
Answer:
Q = 233.42 J
Explanation:
Given data:
Mass of lead = 175 g
Initial temperature = 125.0°C
Final temperature = 22.0°C
Specific heat capacity of lead = 0.01295 J/g.°C
Heat absorbed by water = ?
Solution:
Heat absorbed by water is actually the heat lost by the metal.
Thus, we will calculate the heat lost by metal.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 22.0°C - 125.0°C
ΔT = -103°C
Q = 175 g × 0.01295 J/g.°C×-103°C
Q = -233.42 J
Heat absorbed by the water is 233.42 J.
Answer:

Explanation:
Question 7.
We can use the Combined Gas Laws to solve this question.
a) Data
p₁ = 1.88 atm; p₂ = 2.50 atm
V₁ = 285 mL; V₂ = 435 mL
T₁ = 355 K; T₂ = ?
b) Calculation

Question 8. I
We can use the Ideal Gas Law to solve this question.
pV = nRT
n = m/M
pV = (m/M)RT = mRT/M
a) Data:
p = 4.58 atm
V = 13.0 L
R = 0.082 06 L·atm·K⁻¹mol⁻¹
T = 385 K
M = 46.01 g/mol
(b) Calculation

Given:
No of atoms present= 8.022 x 10^23 atoms
Now we know that 1 mole= 6.022 x 10^23 atoms
Hence number of moles present in 8.022 x 10^23 atoms is calculated as below.
Number of moles
= 8.022 x 10^23/6.022x 10^23
=1.3 moles.
Hence we have 1.3 moles present.
Answer:
Rubidium is used in vacuum tubes as a getter, a material that combines with and removes trace gases from vacuum tubes. It is also used in the manufacture of photocells and in special glasses. Since it is easily ionized, it might be used as a propellant in ion engines on spacecraft.
Symbol: Rb (37)
Atomic Weight: 85.4678
Atomic Number: 37
Number of Stable Isotopes: 1 (View all isotope .