Chemistry is concerned with:
1) Composition
The composition of matter helps determine how it will behave chemically and physically, and is studied in chemistry
2) Structure
The structure of a certain element or compound also governs how the substance behaves, making it another vital aspect of chemistry
3) Behavior
The behavior of substances is studied in order to have explanations presented for it, expanding our understanding.
Answer with Explanation:
Density of copper(Cu)=
Density of zinc(Zn)=
Atomic mass of copper=
Atomic mass of zinc=65.38 g
We know that
Volume=
Using the formula
Volume of copper=
Volume of zinc=
Volume is inversely proportional to the density.
Pre -1982 penny made by copper and post-1982 penny made by zinc.
Therefore, volume of post-1982 penny is greater than the volume of pre-1982 penny because density of zinc is less than the density of copper.
Answer:
3.7 atm
General Formulas and Concepts:
<u>Atomic Structure</u>
<u>Gas Laws</u>
Ideal Gas Law: PV = nRT
- <em>P</em> is pressure
- <em>V</em> is volume
- <em>n</em> is number of moles
- <em>R</em> is gas constant
- <em>T</em> is temperature
Explanation:
<u>Step 1: Define</u>
<em>Identify variables</em>
[Given] <em>n</em> = 0.68 mol H
[Given] <em>T</em> = 298 K
[Given] <em>V</em> = 4.5 L
[Given] <em>R</em> = 0.0821 L · atm · mol⁻¹ · K⁻¹
[Solve] <em>P</em>
<em />
<u>Step 2: Find Pressure</u>
- Substitute in variables [Ideal Gas Law]: P(4.5 L) = (0.68 mol)(0.0821 L · atm · mol⁻¹ · K⁻¹)(298 K)
- Multiply [Cancel out units]: P(4.5 L) = (0.055828 L · atm · K⁻¹)(298 K)
- Multiply [Cancel out units]: P(4.5 L) = 16.6367 L · atm
- Isolate <em>P</em> [Cancel out units]: P = 3.69705 atm
<u>Step 3: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs as our lowest.</em>
3.69705 atm ≈ 3.7 atm