The question is missing the table. Here is the complete question.
The tableshows the concentration of a reactant in the mixture over a period of time.
Reactant Concentration
Time (s) Concentration (M)
0 1.8
210 1.2
450 0.8
580 0.6
720 0.4
What is the average rate of reaction over the first 450 seconds?
A. 1.6x
M
B. 1.9x M
C. 2.0x M
D. 2.2x M
Answer: D. 2.2x M
Explanation: The average rate of a reaction is the rate of change of the concentrations (of reactants or products) in a period of time:
average = - ΔC/Δt
In this case, concentration is negative because it's related to reactant, since its concentration dimishes while the concentration of product increases.
For the first 450 seconds:
Average = 
Average = 
Average = 0.0022
or
Average = 2.2x
So, <u>the Average Rate of the reaction is 2.2x</u><u>M</u>
Answer:
The answer to your question is Cu(NO₃)₂
Explanation:
To write the chemical formula of a molecule:
1.- Look for the symbols of the elements
Copper = Cu has an oxidation number of +2.
Nitrate = NO₃⁻¹ nitrate is a polyatomic ion so it is composed of nitrogen,
oxygen and its oxidation number is -1.
2.- Write the chemical formula and interchange the oxidation numbers.
Cu⁺² + NO₃⁻¹ ⇒ Cu(NO₃)₂
Answer:
n= 0.03 moles
Explanation:
Using the ideal gas law:
PV=nRT
nRT=PV
n= PV/RT
n: moles
P: pressure in atm
V= volume in L
R= Avogadro's constant = 0.0821
T= Temperature in K => ºC+273.15
n= (0.925 atm)(0.80 L) / (0.0821)(300.15 K)
n= 0.03 moles
<span>The part of making a solution that always releases energy is the overall change in forming the solution. The answer is letter D. Although letters A, B and C can be viable answers but, it is not always the case. There are some substances that when you mix or separate them requires more energy or less energy. An example would be w</span>hen the formation (or enthalpy of formation) of carbon
dioxide is negative, it means that it releases heat to the surroundings. When
it releases heat to the surroundings, the reaction is exothermic. Another example is when you mix baking soda and muriatic acid, the resulting mixture is colder. When it is cold, it means that the reaction is endothermic. So the best answer is letter D.
