A reaction in which heat is evolved is an exothermic reaction while a reaction in which heat is absorbed is an endothermic reaction.
In the first case; Na2CO3 + H2SO4, we can see that this is an acid - base reaction therefore it is a neutralization reaction. Since the tube was hot after reaction, heat is given off so it is exothermic.
In the second case; NaOH + H2SO4, we can see that this is an acid - base reaction therefore it is a neutralization reaction. We are told that the tube is not hot but we don't know the initial temperature of the tube or if it was colder than it's initial temperature so we can not make any inference regarding whether the reaction is endothermic or exothermic.
Lastly, the reaction, NaCl + HC2H5OH does not occur so we mark "no reaction". We are told that the tube is not hot but we don't know the initial temperature of the tube or if it was colder than it's initial temperature so we can not make any inference regarding whether the reaction is endothermic or exothermic.
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Answer:
On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you go down a group. As a result, the most electronegative elements are found on the top right of the periodic table, while the least electronegative elements are found on the bottom left.
Explanation:
Answer:
No
Explanation:
In my opinion water doesn't evaporates when is spills on a fabric or a shirt someone is wearing. The fabric or cloth whatever you may call it sucks the water, making you feel your shirt wet. But as the time passes it will slowly dry due to the sun or the warmth surrounding the area the fabric is at.
Answer:
Millimeters
Explanation:
A kilogram is for weight, Milliliters is volume, Kilometers is length but too big for a shoe, so Millimeters is the answer by elimination.
