Answer:
The balanced equation tells us that 1 mole of Zn will produce 1 mole of H2.
1.566 g Zn x (1 mole Zn / 65.38 g Zn) = 0.02395 moles Zn
0.02395 moles Zn x (1 mole H2 / 1 mole Zn) = 0.02395 moles H2 produced
Now use the ideal gas law to find the volume V.
P = 733 mmHg x (1 atm / 760 atm) = 0.964 atm
T = 21 C + 273 = 294 K
PV = nRT
V = nRT/ P = (0.02395 moles H2)(0.0821 L atm / K mole)(294 K) / (0.964 atm) = 0.600 L
Answer:
sweat glands
Explanation:
sweat glands are the only ones that can produce dermcidin, Nacl, urea and ammonia.
Complete Question:
A certain ionic compound X has a solubility in water of .765g/ml at 5 degrees C. Calculate the mass of X that's dissolved in 3 L of a saturated solution of X in the water at this temp. Be sure your answer has the correct unit symbol and significant digits.
Answer:
2.29 kg
Explanation:
A saturated solution is a solution that has the maximum amount of solute diluted at it, so if more solute is added, it will precipitate. The solutions can also be unsaturated (when more solute can be dissolved) or supersaturated (when there is more solute dissolved than the maximum. It's a very unstable solution).
The saturation is measured by the solubility, which indicates how much mass of the solute can be added to a certain volume of the solvent. So, the solubility (S) is the mass (m) divided by the volume (V).
For a solution with 3 L = 3000 mL,
S = m/V
0.765 = m/3000
m = 3000 * 0.765
m = 2295 g
m = 2.29 kg
The idea behind balancing chemical equations is that the number of atoms an element has on the reactants' side must be equal to the number of atoms it has on the products' side.
These atoms will become a part of different compounds once the reaction is completed, but they must always be in equal numbers on both sides.
So, look at iron first. One atom reacts, but two are produced - notice the 2 subscript iron has in Fe2O3. This means you must double the number of atoms on the reactants' side to reach an equality.
2Fe(s)+O2(g)→Fe2O3(s)
Now look at oxygen. Two atoms react, but three are produced. The trick here is to find a common multiple that will make the number of atoms equal on both sides.
The easiest way to do this is to multiply the atoms that react by 3, which will give you 6 oxygen atoms that react, and the atoms that are produced by 2 - this will get you 6 oxygen atoms produced.
2Fe(s)+3O2(g)→2Fe2O3(s)
However, notice that the iron atoms are unbalanced again. You have 2 that react, but 4 that are produced → multiply the atoms that react by 2 again, which will give you
4Fe(s)+3O2(g)→2Fe2O3(s)
