Most of the surface of the earth is covered with water and looks blue from space.
The answer <span>is <span>8.9 g/mL</span>.</span>
The density (D) is <span>equal to mass (m) divided by volume (V): D = m/V
Let's find the mass of the object:
m = 156 g - 105.5 g = 50.5 g
Let's find the volume of the volume:
V = 30.7 mL - 25 mL = 5.7 mL
The density is:
D = m/V = 50.5 g / 5.7 mL = 8.9 g/mL</span>
In this question given concerning the atom's electron, the number of energy sublevels present in the principal energy level n = 4 is to be determined. For this matter, it should be remembered that the number of sublevels of a certain principal energy level is equal to n. For this item, the number of sublevels is also 4. That is s, p, d and f.
<span>To compute 4.659×104−2.14×104, the first step is the factorization. That is as follows:4.659×104−2.14×104= 10^4.(4.659−2.14), the next step is to compute 4.659−2.14=2.51, so 10^4.(4.659−2.14)=2.51x10^4=2.51x 10000 (because10^4=10000), the last calculus is 2.51x 10000=25100, the final answer is 25,000.Hope this helps. Let me know if you need additional help!</span>
Answer:
1360kJ are evolved
Explanation:
When 1mole of H2 reacts with 1/2 moles O2 producing 1 mole of water and 241.8kJ.
To solve this question we need to find the limiting reactant knowing were added 90g of H2 and 90g of O2 as follows:
<em>Moles H2 -Molar mass: 2g/mol-</em>
90g H2 * (1mol / 2g) = 45 moles
<em>Moles O2 -Molar mass: 32g/mol-</em>
90g * (1mol / 32g) = 2.81moles
For a complete reaction of 2.81 moles of O2 are needed:
2.81 moles O2 * (1mol H2 / 1/2 mol O2) = 5.62 moles H2
As there are 45 moles, H2 is the excess reactant and O2 the limiting reactant.
As 1/2 moles O2 produce 241.8kJ, 2.81 moles will produce:
2.81 moles O2 * (241.8kJ / 1/2moles O2) =
<h3>1360kJ are evolved</h3>
