<h3>
Answer:</h3>
0.012 dekameters (dkm)
<h3>
Explanation:</h3>
<u>We are given;</u>
Required to identify the measurements that is not equivalent to 120 cm.
- Centimeters are units that are used to measure length together with other units such as kilometers(km), meters (m), millimeters (mm), dekameters (dkm), etc.
- These units can be inter-converted to one another using suitable conversion factors.
- To do this, we are going to have a table showing the suitable conversion factor from one unit to another.
Kilometer (km)
10
Decimeter (Dm)
10
Hectometer (Hm)\
10
Meter (m)
10
Dekameter (dkm)
10
Centimeter (cm)
10
Millimeter (mm)
Therefore;
To convert cm to km
Conversion factor is 10^5 cm/km
Thus;
120 cm = 120 cm ÷ 10^5 cm/km
= 0.0012 km
To convert cm to dkm
Conversion factor is 10 cm/dkm
Therefore,
120 cm = 120 cm ÷ 10 cm/dkm
= 12 dkm
To convert cm to m
The suitable conversion factor is 10^2 cm/m
Thus,
120 cm = 120 cm ÷ 10^2 cm/m
= 1.2 m
To convert cm to mm
Suitable conversion factor is 10 mm/cm
Therefore;
120 cm = 120 cm × 10 mm/cm
= 1200 mm
Therefore, the measurement that is not equal to 120 cm is 0.012 dkm
Answer:
1. Caffeine, C₈H₁₀N₄O₂
Amount = 1.00/194 = 0.00515 moles
2. Ethanol, C₂H₅OH
Amount = 0.0217 moles
3. Dry Ice, CO₂
amount = 0.0227 moles
<em>Note: The question is incomplete. The compound are as follows:</em>
<em> 1. Caffeine, C₈H₁₀N₄O₂;</em>
<em>2. Ethanol, C₂H₅OH;</em>
<em>3. Dry Ice, CO₂</em>
Explanation:
Amount (moles) = mass in grams /molar mass in grams per mole
1. Caffeine, C₈H₁₀N₄O₂
molar mass of caffeine = 194 g/mol
Amount = 1.00 g/194 g/mol = 0.00515 moles
2. Ethanol, C₂H₅OH
molar mass of ethanol = 46 g/mol
Amount = 1.00 g/46 g/mol = 0.0217 moles
3. Dry Ice, CO₂
molar mass of dry ice = 44 g/mol
amount = 1.00 g/44 g/mol = 0.0227 moles
We will use Arrehenius equation
lnK = lnA -( Ea / RT)
R = gas constant = 8.314 J / mol K
T = temperature = 25 C = 298 K
A = frequency factor
ln A = ln (1.5×10 ^11) = 25.73
Ea = activation energy = 56.9 kj/mol = 56900 J / mol
lnK = 25.73 - (56900 / 8.314 X 298) = 2.76
Taking antilog
K = 15.8
Reaction: 2K₍s₎ + 2H₂O₍l₎ → 2KOH₍aq₎ + H₂₍g₎.
K - potassium.
H₂O - water.
KOH - potassium-hydroxide.
H₂ - hydrogen.
s - solid phase.
l - liquid.
aq - disolves in water.
g - gas.
Reaction is exothermal (release of energy) and potassium burns a purple flame. H<span>ydrogen released during the reaction reacts with </span>oxygen<span> and ignites.</span><span>
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