CO_2 sublimes readily at 25°C. Which properties are usually associated with a compound that undergoes this kind of change?
1 answer:
Explanation:
Sublimation is defined as a process in which solid state of a substance directly changes into vapor or gaseous state without undergoing liquid phase.
For example, naphthalene balls show sublimation at room temperature.
As this process does not cause any change in chemical composition of a substance. Hence, it is known as a physical process.
Similarly, when sublimes readily at
. This shows change in physical state of carbon dioxide is taking place, i.e, from solid to gaseous phase.
Thus, we can conclude that when sublimes readily at
then it means physical properties are usually associated with a compound that undergoes this kind of change.
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(a) f = 5.00 × 10²⁰ Hz, E = 3.32 × 10⁻¹³ J;
(b) f = 1.20 × 10¹⁰ Hz, E = 7.96 × 10⁻²⁴J.
<h3>Explanation</h3>What's the similarity between a gamma ray and a microwave?
Both gamma rays and microwave rays are electromagnetic radiations. Both travel at the speed of light at in vacuum.
where
- f is the frequency of the electromagnetic radiation,
- c is the speed of light, and
is the wavelength of the radiation.
(a)
Convert all units to standard ones.
.
The unit of shall also be standard.
.
For each particle,
,
where
is the energy of the particle,
is the planck's constant where
, and
is the frequency of the particle.
.
(b)
Try the steps in (a) for this beam of microwave with
.
Expect the following results:
, and
.
Answer:
15.9 g
Explanation:
(Take the atomic mass of C=12.0, H=1.0, O=16.0)
no. of moles = mass / molar mass
no. of moles of octane used = 11.2 / (12.0x8 + 1x18)
= 0.0982456 mol
Since oxygen is in excess and octane is the limiting reagent, the no. of moles of H2O depends on the no. of moles of octane used.
From the balanced equation, the mole ratio of octane : water = 2:18 = 1: 9,
so this means, one mole of octane produced 9 moles of water.
Using this ratio, we can deduce that (y is the no. of moles of water produced):
y = 0.0982456x9
y= 0.88421 mol
Since mass = no. of moles x molar mass,
mass of water produced = 0.88421 x (1.0x2+16.0)
=15.9 g