I would say Na. Oxygen has 2 valence electrons and when reacting with other molecules, the ones with the fullest or emptiest shells will react the least. Both H2 and Na are in the Alkali Metals in the first row, but since H2 has 2 molecules, it would use more oxygen than Ana
1.39 g HCl
Explanation:
The balanced chemical equation for this reaction is given by
Zn(<em>s</em>) + 2HCl(<em>aq</em>) ---> ZnCl2(<em>aq</em>) + H2(<em>g</em>)
Convert the # of grams of Zn to moles:
1.25 g Zn × (1 mol Zn/65.38 g Zn) = 0.0191 mol Zn
Use the molar ratio to find the # of moles of HCl needed to react completely with the given amount of Zn:
0.0191 mol Zn × (2 mol HCl/1 mol Zn) = 0.0382 mol HCl
Convert this amount to grams:
0.0382 mol HCl × (36.458 g HCl/1 mol HCl) = 1.39 g HCl
Answer:
fitness. the ability of an organism to survive and reproduce in its environment. adaptation. the inherited characteristic that increases an organism's chance of survival.
1) Answer: A hot pack feels warm when chemicals in it combine.
Explanation: Reactions or process in which heat is released(produced) are known as exothermic reactions or process and those in which the heat is absorbed are known as endothermic reactions or process.
If a beaker feels cools when chemical in it react then it means the chemicals have absorbed the heat energy from its surroundings and so it is an example of an endothermic process.
A hot pack feels warm when chemicals in it combine means the energy is released in the chemical reaction and so it is an example of an exothermic process.
Plants use the sun's energy for photosynthesis which is a process of forming food for the plants. Energy acts as a reactant in this process and so it is an example of endothermic process.
Frying an egg by heating it on a stove is an example of an endothermic process as the heat is required to fry the egg.
So, the only exothermic process is the second one, "A hot pack feels warm when chemicals in it combine."
2) In the given equation, heat is written as a product means the heat is released in the equation and so it is an example of an exothermic reaction.
So, the correct choice is the last one " It is exothermic because energy is released."
Answer:
Explanation:
AgNO3 + NaCl --> AgCl + NaNO3
Number of moles
AgNO3
= molar concentration * volume
= 1 * 0.01
= 0.01 mol
NaCl
= 0.01 * 1
= 0.01 mol.
By stoichiometry, 1 mole of silver nitrate reacted with 1 mole of NaCl. Therefore,
Number of moles of AgCl formed = 0.01 × 1
= 0.01 mol AgCl formed.
Heat absorbed by solution during precipitation:
Mass of solution = density × total volume
= 1 × 20
= 20 g.
q = m * Cp * (T2 - T1)
= 20 * 4.18 * (32.6 - 25.0)
= 635 J
Since 635 J was absorbed by the solution, the reaction released -635 J
So, Delta H = -635 J/0.01 mol
= -63500 J/mol
= -63.5 kJ/mol.
