Answer:
Explanation:
The answer choices are:
<h2>Solution</h2>
You must use the conversion factors to convert J to kcal.
Dividing both sides by 4.184J:
⇒ 1 = 1cal/4.184J
Dividing both sides by 1,000 cal
⇒ 1 = 1kcal / 1,000 cal
Mutiply<em> 578J</em> by the conversion factors to find <em>kcal</em>:
Notice how the units J and cal cancel to yield kcal at the end.
5.4 x 10²³ molecules
Explanation:
Given parameter
Volume of gas = 20L
Condition of reaction = STP
Unknown:
number of molecules
Solution:
The number of molecules of a substance is given by;
Number of molecules = Number of moles x avogadro's constant
Number of moles at stp = 
Number of moles of SO₂ = 
= 0.893mole
Number of molecules = 0.893 x 6.02 x 10²³ = 5.4 x 10²³ molecules
learn more:
Number of molecules brainly.com/question/10818009
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Answer:
D. chemical alters the atomic structure of a substance, while physical does not
hope this helps!
Answer:
2 moles
Explanation:
number of mole =mass /molar mass
mass=36
molar mass=(2*1)+16=18
therefore, no of mole =36÷18 =2
C. The design would not be cost-efficient; the plane would require more fuel due to increased thrust from higher drag.
