Answer:
d. 97.60 g
Explanation:
Given parameters:
Number of moles of formaldehyde = 3.25moles
Ratio:
C H O
1 2 1
Unknown:
Mass of this sample = ?
Solution:
The empirical formula of a compound is its simplest formula. It is the simplest whole number ratio of the atoms in a given substance.
The molecular formula is the actual formula of the compound.
Since the molecular and empirical formula are the same here, the formula of the compound is;
CH₂O
To find the mass of the formaldehyde, use the expression below;
Mass = number of moles x molar mass
molar mass of CH₂O = 12 + 2(1) + 16 = 30g/mol
Mass = 3.25 x 30 = 97.5g
Answer:
B) 8.0 molecules.
Explanation:
- From the balanced equation: <em>3Cu + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O,</em>
It is clear that 3.0 atoms of Cu react with 8.0 molecules of HNO₃ to produce 3.0 molecules of Cu(NO₃)₂, 2.0 molecules of NO, and 4.0 atoms of H₂O.
<u><em>Note that: </em></u>The no. of atoms and molecules is the same ratio to the no. of moles.
<u><em>Using cross multiplication:</em></u>
3.0 atoms of Cu produce → 2.0 molecules of NO, from the balanced equation.
12.0 atoms of Cu produce → <em>??? molecules of NO.</em>
<em>∴ The no. of molecules of NO produced </em>= (2.0 molecules)(12.0 atoms)/(3.0 atoms) = <em>8.0 molecules.</em>
D. Appalachians
That should be your answer for the mountainous northern coast.
In the sliding filament model of muscle contraction, the myofilaments slide over each other, resulting in the overlapping of actin and <span>myosin. Hope this helps. Have a nice day. Feel free to ask more questions. Thank you.</span>
