Answer:
1. From water vapor to the dry ice;
2. The potential energy is higher before the water vapor condenses;
3. The thermal energy is higher in the 2.0 kg block.
Explanation:
1. The heat flows from the system with high temperature to the system with low temperature. The water vapor is at 298 K, and the dry ice is at 194.5 K.
2. The energy of the molecules is related to the temperature and the physics state. At the gas state, the molecules are more agitated, and the energy is higher than the liquid state. So, when the vapor condenses to a liquid, the energy decreases.
3. The thermal energy can be calculated by:
Q = m*c*ΔT
Where m is the mass, c is the specific heat, and ΔT the variation in the temperature. So, when the mass increase, thermal energy also increases.
Answer:
The correct answers are:
a) 180 g
b) 93.7 cm³
Explanation:
The density of a substance is the mass of the substance per unit of volume. So, it is calculated as follows:
density= mass/volume
From the data provided in the problem:
density = 0.8 g/cm³
a) Given: volume= 225 cm³
mass= density x volume = 0.8 g/cm³ x 225 cm³ = 180 g
b) Given: mass= 75.0 g
volume = mass/density = 75.0 g/(0.8 g/cm³)= 93.75 cm³≅ 93.7 cm³
Answer:
= 459.1 nm
This wavelength corresponds to yellow color and thus gold has warm yellow color.
Explanation:
Given that:- Energy = 2.7 eV
Energy in eV can be converted to energy in J as:
1 eV = 1.602 × 10⁻¹⁹ J
So, Energy = 
Considering:-
Where,
h is Plank's constant having value 
c is the speed of light having value 
is the wavelength of the light
So,
= 459.1 nm
This wavelength corresponds to yellow color and thus gold has warm yellow color.
<span>Molar mass(C)= 12.0 g/mol
Molar mass (O2)=2*16.0=32.0 g/mol
Molar mass (CO2)=44.0 g/mol
18g C*1mol C/12 g C = 1.5 mol C
C + O2 → CO2
from reaction 1 mol 1 mol 1 mol
from problem 1.5 mol 1.5 mol 1.5 mol
1.5 mol O2*32 g O2/1 mol O2 = 48 g O2
In reality this reaction requires only 48 g O2 for 18 g carbon.
And from 18 g carbon you can get only
1.5 mol CO2*44 g CO2/1 mol CO2=66 g CO2
But these problem has 72g CO2. The best that we can think, it is a mix of CO2 and O2.
So to find all amount of O2 that was added for the reaction (probably people who wrote this problem wanted this)
we need (the mix of 72g - mass of carbon 18 g)= 54 g.
So the only answer that is possible is </span><span>2.) 54 g.</span>
Answer: they are the same.
Explanation:
1) Sucrose is a compound with chemical formula C₁₂H₂₂O₁₁
2) That means that all molcules of sucrose will have the same kind of atoms in the same proportion, whic is to say same composition:
12 atoms of C: 22 atoms of H: 11 atoms of O, per each molecule of sucrose.
3) For this question you can rely in the definition of compound: a pure substance formed by the combination of two or more elements always in the same ratio (same composition).
4) That also implies, that all the molecules of sucrose have the same properties.
