Hey there!
1. A chemical reaction is, B).<span> Any time different substances combine to form a new substance, or when a substance breaks up into different substances
2.</span> Balancing chemical equations is called, C). <span>Equivalentry
3.</span><span> Sulfuric acid is made of two hydrogen atoms (H), one sulfur atom (5), and four oxygen atoms (0). What is its formula? C). </span><span>H2S04
Hope this helps!
-Much love, Makayla</span>
Answer:
w = -531 kJ
1. Work was done by the system.
Explanation:
Step 1: Given data
- Heat gained by the system (q): 687 kJ (By convention, when the system absorbs heat, q > 0).
- Change in the internal energy of the system (ΔU°): 156 kJ
Step 2: Calculate the work done (w)
We will use the following expression.
ΔU° = q + w
w = ΔU° - q
w = 156 kJ - 687 kJ
w = -531 kJ
By convention, when w < 0, work is done by the system on the surroundings.
Transcribed image text: Four liquids are described in the table below. Use the second column of the table to explain the order of their freezing points, and the third column to explain the order of their boiling points. For example, select '1' in the second column next to the liquid with the lowest freezing point. Select '2' in the second column next to the liquid with the next higher freezing point, and so on. In the third column, select '1' next to the liquid with the lowest boiling point, '2' next to the liquid with the next higher boiling point, and so on. Note: the density of water is 1.00g/mL .
2H₂ + O₂ = 2H₂O
n(H₂)=m(H₂)/M(H₂)
n(H₂)=5g/2.0g/mol=2.5 mol
n(O₂)=m(O₂)/M(O₂)
n(O₂)=40g/32.0g/mol=1.25 mol
H₂ : O₂ = 2 : 1
2.5 : 1.25 = 2 : 1
n(H₂O)=n(H₂)=2n(O₂)=2.5 mol
m(H₂O)=n(H₂O)M(H₂O)
m(H₂O)=2.5mol*18.0g/mol=45.0 g
<h3>During physical changes, the composition od the original substance is not altered, but the properties of the original substance are altered. During a chemical change the composition od the original substance is not altered and the change is irreversible. Melting of butter and wax is an example of chemical changes.</h3>
