Answer:
Helium, this noble gas has the least density at STP
Explanation:
Answer: The correct answer is: " endothermic . "
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<u>Note</u>: Heat flows <u> into </u> [heat <u> may be </u> absorbed within] an "<u>endothermic</u>" reaction or system
To the contrary, heat flows <u> </u><u>out </u> [heat <u> may </u><em> </em>exit from or <u> may be </u> released from] an "<u>exothermic</u>" reaction or process.
<u>Hint</u>: Think of the "prefixes" of: "<u>endo</u>thermic" and "<u>exo</u>thermic" :
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1) endo- = "within" (as in "endothermic" —heat tends to be absorbed/"within"/"released within"/released within"/into" ;
2) exo- = " outwards"/"exit" (as in "exothermic") —heat tends to '"exit"/leave/escape from/"be released out of/form".
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Hope this is helpful to you!
Best wishes to you in your academic pursuits
—and within the "Brainly" community"!
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Answer:
441.28 g Oxygen
Explanation:
- The combustion of hydrogen gives water as the product.
- The equation for the reaction is;
2H₂(g) + O₂(g) → 2H₂O(l)
Mass of hydrogen = 55.6 g
Number of moles of hydrogen
Moles = Mass/Molar mass
= 55.6 g ÷ 2.016 g/mol
= 27.8 moles
The mole ratio of Hydrogen to Oxygen is 2:1
Therefore;
Number of moles of oxygen = 27.5794 moles ÷ 2
= 13.790 moles
Mass of oxygen gas will therefore be;
Mass = Number of moles × Molar mass
Molar mass of oxygen gas is 32 g/mol
Mass = 13.790 moles × 32 g/mol
<h3> = 441.28 g</h3><h3>Alternatively:</h3>
Mass of hydrogen + mass of oxygen = Mass of water
Therefore;
Mass of oxygen = Mass of water - mass of hydrogen
= 497 g - 55.6 g
<h3> = 441.4 g </h3>
You convert kinetic energy into thermal energy when you rub two sticks together.