All the elements in one group have the same number of valence electrons.
The balanced chemical reaction is:
<span>2C4H10(g)+13O2(g)->10H2O(g)+8CO2(g)
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<span>Calculate the mass of water produced when 1.77 grams of butane reacts with excessive oxygen?
</span>1.77 g C4H10 (1 mol C4H10/58.14 g C4H10) (10 mol H2O / 2 mol C4H10) ( 1.01 g H2O / 1 mol H2O ) = <span>0.15 g H2O
</span><span>Calculate the mass of butane needed to produce 71.6 of carbon dioxide.
</span>71.6 g CO2 (1 mol CO2/ 44.01 g CO2) ( 2 mol C4H10 / 8 mol CO2 ) (58.14 g C4H10 / 1 mol C4H10 ) = 23.65 g C4H10
The condition at which the entropy of a pure solid will be zero is<span> when a substance is at absolute zero. Absolute zero is </span><span>the lowest temperature that is theoretically possible, at which the motion of particles which constitutes heat would be minimal. It is zero on the Kelvin scale, equivalent to −273.15°C.</span>
The correct answer for this question is this one: " a.The solution has a volume of 25 mL "
The observation that shows a quantitative observation is when you are talking about numeric data. Just like this one, <em>The solution has a volume of 25 mL </em>
Hope this helps answer your question and have a nice day ahead.