Answer: 5,600 J
Explanation:
Joules = mass x specific heat x temperature change
32 x 4.184 x (54 - 12)
= 133.888 x 42
= 5,623.296
(significant figures => 5,600)
There are quite a bunch of typo errors in the question; here is the correct question below:
A thermos bottle (Dewar vessel) has an evacuated space between its inner and outer walls to diminish the rate of transfer of thermal energy to or from the bottle’s contents. For good insulation, the mean free path of the residual gas (air; average molecular mass = 29) should be at least 10 times the distance between the inner and outer walls, which is about 1.0 cm. What should be the maximum residual gas pressure in the evacuated space if T = 300 K? Take an average diameter of d = 3.1 × 10⁻¹⁰ m for the molecules in the air.
Answer:
9.57 × 10⁻⁷ atm
Explanation:
The mean free path ( λ ) can be illustrated by the equation:
λ = ---------- (1)
N/V = ------------- (2)
From the above relation, we can deduce that;
P= -------------(3)
let I= λ
From the above equations;
d= diameter of the atom
= avogadro's constant
P= pressure
R= universal rate constant which is given by 0.08206 L atm mol⁻¹ k⁻¹
T= temperature
From the question, we are given that the mean free path of the residual air molecules ( d = 3.1 × 10⁻¹⁰ m) is equal to 10cm = 0.1m
Therefore, we can determine the pressure using equation (3)
i.e
P=
=
=97.06 × 10⁻³ Pa ×
=9.57 × 10⁻⁷ atm
Therefore, the maximum residual gas pressure in the calculated space is; 9.57 × 10⁻⁷ atm
D. is the missing element.
Carlos <em>hasn’t done research</em> on what other scientists have observed and investigated on this topic. If he hasn’t done his literature research, he may just be repeating the experiments of other scientists working in the same area.
Options “A.”, “B.”, and “C.” are all part of the scientific method.
The balanced chemical reactions are:
Further Explanation:
The following reactions will undergo double displacement where the metal cations in each compound are exchanged and form new products.
For reaction 1, the compounds involved are nitrates and chlorides. To determine the states of the products, the solubility rules for nitrates and chlorides must be followed:
- All nitrates are generally soluble.
- Chlorides are generally soluble except AgCl, PbCl2, and Hg2Cl2.
Therefore, the products will have the following characteristics:
- silver chloride (AgCl) is insoluble
- sodium nitrate (NaNO3) is soluble
For reaction 2, the compounds involved are phosphates and chlorides. The solubility rules for phosphates and chlorides are as follows:
- Phosphates are generally insoluble except for Group 1 phosphates.
- Chlorides are generally soluble except for AgCl, PbCl2, and Hg2Cl2.
Hence, the products of the second reaction will have the following characteristics:
- potassium chloride (KCl) is soluble
- magnesium phosphate is insoluble
Insoluble substances are denoted by the symbols (s) in a chemical equation. The soluble substances are denoted as <em>(aq).</em>
Learn More
- Learn more about solubility brainly.com/question/1163248
- Learn more about solubility rules brainly.com/question/1447161
- Learn more about net ionic equations brainly.com/question/12980075
Keywords: solubility rules, precipitation reaction