Answer:

Explanation:
number of moles of C8H9NO2 = 
The trick is to remember to convert milligrams to grams because molar mass is normally presented in grams per mole
Answer:
read it first
Explanation:
Population change is governed by the balance between birth rates and death rates. If the birth rate stays the same and the death rate decreases, then population numbers will grow. If the birth rate increases and the death rate stays the same, then population will also grow.
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Atoms of elements that are nonmetals tend to gain electrons and atoms of metallic elements tend to lose electrons. Metals have few electrons in their valence shells.
By losing those electrons, these metals achieve noble gas configuration and satisfy the octet rule.
Nonmetals that have close to 8 electrons in their valence shells readily accept electrons to achieve noble gas configuration.
An example is the reaction between calcium and oxygen. Calcium is a metal and has 2 valence electrons. Oxygen is a nonmetal and has 6 valence electrons.
Calcium gives up its two valence electrons and oxygen accepts them and an ionic bond is established resulting in the formation of anew compound namely calcium oxide.
It’s a or b i think it’s b
V(C₄H₆O₃) = 5.00 mL.
d(C₄H₆O₃) = 1.08 g/mL.
m(C₄H₆O₃) = V(C₄H₆O₃) · d(C₄H₆O₃).
m(C₄H₆O₃) = 5.00 mL · 1.08 g/mL.
m(C₄H₆O₃) = 5.4 g.
n(C₄H₆O₃) = m(C₄H₆O₃) ÷ M(C₄H₆O₃).
n(C₄H₆O₃) = 5.4 g ÷ 102 g/mol.
n(C₄H₆O₃) = 0.0529 mol.
n(C₇H₆O₃) = 2.08 g ÷ 138.1 g/mol.
n(C₇H₆O₃) = 0.015 mol; limiting reactant.
From chemical reaction: n(C₄H₆O₃) : n(C₉H₈O₄) = 1 : 1.
n(C₉H₈O₄) = 0.015 mol.
m(C₉H₈O₄) = 0.015 mol · 180.16 g/mol.
m(C₉H₈O₄) = 2.71 g; theoretical yield.
percent yield od aspirine = 2.57 g ÷ 2.71 g · 100% = 94.83%.