Answer:
3.87 mol N
General Formulas and Concepts:
<u>Chemistry - Atomic Structure</u>
- Reading a Periodic Table
- Using Dimensional Analysis
Explanation:
<u>Step 1: Define</u>
54.2 g N
<u>Step 2: Identify Conversions</u>
Molar Mass of N - 14.01 g/mol
<u>Step 3: Convert</u>
<u />
= 3.86867 mol N
<u>Step 4: Check</u>
<em>We are given 3 sig figs. Follow sig fig rules and round.</em>
3.86867 mol N ≈ 3.87 mol N
The composite material is composed of carbon fiber and epoxy resins. Now, density is an intensive unit. So, to approach this problem, let's assume there is 1 gram of composite material. Thus, mass carbon + mass epoxy = 1 g.
Volume of composite material = 1 g / 1.615 g/cm³ = 0.619 cm³
Volume of carbon fibers = x g / 1.74 g/cm³
Volume of epoxy resin = (1 - x) g / 1.21 g/cm³
a.) V of composite = V of carbon fibers + V of epoxy resin
0.619 = x/1.74 + (1-x)/1.21
Solve for x,
x = 0.824 g carbon fibers
1-x = 0.176 g epoxy resins
Vol % of carbon fibers = [(0.824/1.74) ÷ 0.619]*100 =<em> 76.5%</em>
b.) Weight % of epoxy = 0.176 g epoxy/1 g composite * 100 = <em>17.6%</em>
Weight % of carbon fibers = 0.824 g carbon/1 g composite * 100 = <em>82.4%</em>
Answer:
[CO₂] = 375 ppm
Explanation:
We can determine the concentration in value of ppm
ppm = mass of solute (mg) / mass of solution (kg)
Solution: atmosphere
Solute: CO₂
We convert the mass of CO₂ from g to mg → 0.1875 g . 1000 mg / 1g = 187.5 mg
We convert the mass of the atmosphere from g to kg: 500 g . 1 kg/1000g = 0.500 kg
ppm = 187.5 mg / 0.500kg = 375
The correct answer for this question is +3OH
Answer:
<u>89.6 L</u>
Explanation:
In normal conditions,
<u><em>For every </em></u><u><em>1 mole</em></u><u><em> of carbon dioxide at STP, it occupies </em></u><u><em>22.4 L</em></u><u><em> of volume.</em></u>
<u><em /></u>
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Solving :
⇒ 1 mole : 22.4 L
⇒ 1 × 4 : 22.4 × 4
⇒ 4 moles : <u>89.6 L</u>
