<span>We can use rocks to determine if the animals from to day have changed from the past.
Rocks also help us know if rivers once flowed through an area.
We use them to find out what type of animals live then that are extinct now.</span>
Given parameters:
Heat of fusion of water = 334j/g
Mass of ice = 45g
Temperature of ice = 0.0°c
Unknown:
Amount of heat needed to melt = ?
Solution:
This is simply a phase change and a latent heat is required in this process.
To solve this problem; use the mathematical expression below;
H = mL
where m is the mass
L is the heat of fusion of water;
H = 45 x 334 = 15030J
Answer:
0.8078 Kg
Explanation:
Pressure of water = 0.15 MPa = 1.5 bar
At critical point of water ,temperature = 647 K=374°C
From the ideal gas equation
P×V= m×R×T
Let us assume volume = 1 m^3
1.5 x 105 x 1 = m x 287 x 647
m= 0.8078 kg
the fraction of mass of liquid at 25°C.
Answer:
The gas that Dr. Brightguy added was O₂
Explanation:
Ideal Gases Law to solve this:
P . V = n . R . T
Firstly, let's convert 736 Torr in atm
736 Torr is atmospheric pressure = 1 atm
20°C = 273 + 20 = 293 T°K
125 mL = 0.125L
0.125 L . 1 atm = n . 0.082 L.atm / mol.K . 293K
(0.125L .1atm) / (0.082 mol.K /L.atm . 293K) = n
5.20x10⁻³ mol = n
mass / mol = molar mass
0.1727 g / 5.20x10⁻³ mol = 33.2 g/m
This molar mass corresponds nearly to O₂
Answer:
francium
Explanation:
the atomic radius increases from top to bottom in a group, and decreases from left to right across a period.
