an atom because its the smallest thing in the entire world and in all orgnaisms
B. Fossil
Why? Well skeleton seems like another answer BUT the definition of a fossil is an imprint of an organism on rock.
Example: A dinosaur presses it’s foot in dirt and it leaves a footprint or ‘fossil’ behind
Answer: A and D
Explanation: isotopes must have same atomic number but different mass number due to the difference in their Neutron number
The balanced chemical reaction is expressed as:
<span>4hcl(g)+o2(g)→2h2o(l)+2cl2(g)
To determine the percent yield of the reaction, we need to calculate for the theoretical yield. This is the maximum amount of the product that can be produced from the reaction given the initial amounts of the reactants. First, we identify the limiting reactant as follows:
</span><span>63.1 g of hcl ( 1 mol / 36.46 g ) ( 1 mol O2 / 4 mol HCl) ( 32 g / mol) = 13.85 g O2
17.2 g of o2 ( 1 mol / 32 g ) ( 4 mol HCl / 1 mol O2) ( 36.46 g / mol) = 78.39 g HCl
Therefore, the limiting reactant would be HCl. We use the value for the HCl to calculate for the theoretical yield.
</span>63.1 g of hcl ( 1 mol / 36.46 g ) ( 2 mol Cl2 / 4 mol HCl) ( 70.9 g / mol ) = 61.35 g Cl2
Percent yield = actual / theoretical x 100
= 59.6 / 61.35 x 100
= 97.1%
To answer this problem, we must make assumptions for simplicity. The first assumption is that, the system only consist of these 3 gases. The second assumption is that, these gases behave ideally. Thus, from Dalton's Law of Partial Pressure, the total pressure is simply the sum of their individual partial pressures.
Total pressure = 2.5 + 0.8 + 3.4 = <em>6.7 atm</em>
