Answer;
=28.09 amu
Explanation;
In this problem, they did not give us the percentages. However, since we know the number of atoms, we can easily calculate the percentages. For example:
(460 X 100)/500 = 92%
If we do this for all three isotopes,
(460 × 25)/500 = 5 %
(460 × 15) /500 = 3%
-We get 92%, 5%, and 3%. (We'll assume these are absolute numbers for determining our significant figures).
Now the problem is just like the previous one. First convert the percentages into decimals. Then multiply those decimals by the masses and add. Here's the solution:
= (0.92) X (27.98 amu) + (0.05) X (28.98 amu) + (0.03) X (29.97 amu)
= 25.74 amu + 1.449 amu + 0.8991 amu
= 28.09 amu
Answer:
24x10³
Explanation:
2CO₂(g) + 4H₂O(g) → 2CH₃OH(l) + 3O₂ (g)
The equilibrium constant for this reaction is:
Kc = ![\frac{[O_2]^3}{[CO_2]^2[H_2O]^4}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BO_2%5D%5E3%7D%7B%5BCO_2%5D%5E2%5BH_2O%5D%5E4%7D)
The expression of [CH₃OH] is left out as it is a pure liquid.
Now we <u>convert the given masses of the relevant species into moles</u>, using their <em>respective molar masses</em>:
- CO₂ ⇒ 3.28 g ÷ 44 g/mol = 0.0745 mol CO₂
- H₂O ⇒ 3.86 g ÷ 18 g/mol = 0.214 mol H₂O
- O₂ ⇒ 2.80 g ÷ 32 g/mol = 0.0875 mol O₂
Then we calculate the concentrations:
- [CO₂] = 0.0745 mol / 7.5 L = 0.0099 M
- [H₂O] = 0.214 mol / 7.5 L = 0.0285 M
- [O₂] = 0.0875 mol / 7.5 L = 0.0117 M
Finally we <u>calculate Kc</u>:
- Kc =
= 24x10³
Answer:
Heating of the liquid water in a microwave.
Explanation:
Radiation is a form of heat transfer process that does not require a material medium rather it travels through space or vacuum in the form of electromagnetic waves or radiation. Heat transfer by radiation occurs in the form of microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed. Some common examples of heat transfer by radiation is the warming of the Earth by the Sun, the warmth one experiences while sitting by the campfire, or the heating up of foods in a microwave.
Black bodies or surfaces are good absorbers as well as emitters of radiation. On the other shiny or white surfaces are poor radiators of heat.
From the above discussion on radiation, it can be seen that when the chemist takes the liquid and heats it in a microwave, the heat absorbed by the liquid to change to gaseous state is transferred through radiation.
Ans: Final volume = 25.0 ml
<u>Given:</u>
Initial volume V1 = 50.0 ml
Initial pressure P1 = 20.0 atm
Final pressure P2 = 40.0 atm
<u>To determine:</u>
The final volume V2
<u>Explanation:</u>
Ideal gas equation: PV = nRT
under constant temperature, T and number of moles n we have:
PV = constant
or, P1V1 = P2V2
V2 = P1V1/P2 = 20*50/40 = 25 ml.
Coefficients in a chemical equation express RATIOS between molecules or compounds.
In chemical equations, coefficient refers to those numerical numbers that are usually written at the front of elements' chemical symbols in order to balance the equations. Coefficients tell us the number of a particular element that must react with a specific number of another element in order for certain amount of chemical products to be produced; that is, it provide information about the reaction ratio of reactants and products. For instance, look at this chemical equation: N2 + 3H2 = 2NH3
In the equation given above, the coefficient of N2 is 1, the coefficient of H2 is 3 and the coefficient of NH3 is 2. What this equation is essentially telling us is that, in order to produce two molecules of ammonia, one molecule of nitrogen must react with three molecules of hydrogen. Thus, the equation gives the ratios between the product and the reactants.
