Answer:
Please find the detailed explanation below
Explanation:
A scientific method is a sequence of steps that is used to solve a problem. Every scientific method begins with a problem that needs to be solved.
Hence, in order to determine whether water really does take longer to boil if you are watching it, we employ the steps involved in a scientific method.
1) Ask a question/Make observation: This must initiate the process. The observation/question made here is that DOES WATER TAKE LONGER TIME TO BOIL WHEN WATCHED?
2. Formulating hypothesis; an hypothesis is a testable prediction of a possible solution to the stated problem. In this case, an hypothesis could read: IF water is watched while boiling, THEN it will take a longer time to boil. A hypothesis must be tested for it to be proved or disproved.
3. Test hypothesis: The formulated hypothesis is tested via conducting an experiment. The set up of the experiment can involve one group where water is boiled while watching it and another where water is boiled without watching. The former group is called Experimental group, while the latter group is called Control group. The time it takes for each group of water to boil will be recorded.
The independent variable (manipulated variable) will be the WATCHING, while the dependent variable (tested/responding variable) will be the TIME IT TAKES FOR WATER TO BOIL
4. Analyse the data; the data refers to the recorded time for each group of water. This will be analysed and compared.
5. Make conclusion; the conclusion depends on the result, which is the recorded time for each group of boiled water. Based on the result, the hypothesis can either be rejected or accepted. For example, if the control group boils faster than the experimental group, our hypothesis will be accepted but if otherwise, the hypothesis will be rejected.
Therefore, via the scientific method, it can be determined if it really takes longer time for water to boil while watched.
One gallon of gasoline in an automobiles engine produces on average 9.50 kg of carbon dioxide, which is a greenhouse gas; that is, it promotes the warming of Earth's atmosphere. Calculate the annual production of carbon dioxide in kilograms if there are exactly 40.0 million cars in the United States and each car covers a distance of 7930 mi at a consumption rate of 23.6 miles per gallon. Enter your answer in scientific notation.
Answer:
The value is [tex]U =1.3908 *10^{11} \ kg [/tex]
Explanation:
From the question we are told that
mass of carbon dioxide produced by one gallon of gasoline is [tex]m = 9.50 \ kg[/tex]
The number of cars is [tex]N = 40 \ million = 40 *10^{6} \ cars[/tex]
The distance covered by each car is [tex]d = 7930 \ mi[/tex]
The rate is [tex]R = 23.6 \ mi/ gallon[/tex]
Generally the amount of gasoline used by one car is mathematically represented as
[tex]G = \frac{d}{R}[/tex]
=> [tex]G = \frac{7930}{23.6}[/tex]
=> [tex]G = 366 \ gallons [/tex]
Generally the amount of gasoline used by N cars is
[tex]H = N * G[/tex]
=> [tex]H = 40*10^{6} * 366[/tex]
=> [tex]H = 1.464*10^{10} \ gallons [/tex]
Generally the annual production of carbon dioxide is mathematically represented as
[tex]U = m * H[/tex]
=> [tex]U =9.50 * 1.464*10^{10}[/tex]
=> [tex]U =1.3908 *10^{11} \ kg [/tex]
An atom has 17 protons and 18 neutrons.
Which symbol represents that atom, including its mass number?
Question 15 options:
Cl-32
Cl-35
S-34
Ar-33
Answer: Cl-35
Explanation:
The table below shows air pressure measurements taken at set altitudes above sea level. What fact about Earth’s atmosphere best explains this data according to the table? Question 3 options: As altitude increases in the atmosphere, temperature changes from layer to layer. As altitude increases, there is less air pushing down from above, which decreases the pressure. As altitude increases, the composition of the atmosphere changes so that lighter-weight gases make up the majority of the air. At higher altitudes, there is less water vapor in the air which changes the air pressure.
Answer: As altitude increases, there is less air pushing down from above, which decreases the pressure.
Explanation:
Atmospheric pressure is the result of air particles being pulled to the surface of the Earth by gravity. As they are pulled, they will exert more pressure on the Earth and this is what atmospheric pressure is.
It makes sense therefore that as we move higher into the atmosphere, the atmospheric pressure will decrease because less air particles are exerting pressure as we go further off the ground.
Another way to look at it is that there is air in the earth's atmosphere and all that air has weight that is pushing down on us. As we go higher into the atmosphere, there'll be less air pushing down on us so the weight will be less.
Answer:
A as te altitude increases
Explanation:
Place the following substances in order of increasing vapor pressure at a given temperature.
a. NF3,
b. NH3,
c. BCl3.
Answer:
NH3 < NF3 < BCl3
Explanation:
The vapour pressure of a substance has something to do with the nature of intermolecular forces between its molecules. If the molecules of a substance are held together by strong intermolecular forces, the substance will display a low vapour pressure at a given temperature and vice versa.
Ammonia has the lowest vapour pressure because of strong intermolecular hydrogen bonds that hold its molecules together.
The trend for increasing vapor pressure will be:
NH₃<NF₃<BCl₃
We know that,
The stronger the intermolecular forces, the lower the vapor pressure, and the higher the boiling point.
Thus to solve this question we need to look the intermolecular attractions in the given molecules.
1. In ammonia molecule, since it is polar in nature. It exhibits, dipole-dipole interactions and also there is hydrogen bonding between nitrogen and hydrogen atoms. So these interactions are strongest thus NH₃ will have lower value of vapor pressure.
2. Forces of attractions in NF₃ is also stronger in comparison to BCl₃ but weaker than NH₃ thus in terms of vapor pressure it will come after NH₃.
3. Lastly, in BCl₃ it is a non-polar molecule; it exhibits London forces which are the weakest thus it will have the higher value of vapor pressure.
Trend for intermolecular attraction:
ion-dipole>hydrogen bonding>dipole-dipole> London forces > Van der Waals forces
Therefore,
Increasing order of vapor pressure will be:
NH₃<NF₃<BCl₃
Learn more:
https://brainly.com/question/14220340
What is the systematic name of Mg(NO3)2?A) Manganese nitrite.B) Magnesium nitrite.C) Magnesium nitrate.D) Manganese nitrate.
Which element has a greater
ionization energy Manganese (Mn) or Selenium (Se)?
Answer:
manganese has greater ionization energy than Selenium
Which set contains non-equivalent members?A) enthalpy and heat contentB) endothermic reaction and +HC) exothermic reaction and -HD) kinetic energy and energy of motionE) high energy and high stability
Answer:
E
Explanation:
Here in this question, what we will do is to select which of the pairs that do not correlate.
A. Enthalpy and heat content
This two terms are at par with each other. By definition, the enthalpy of a system simply is the total amount of heat content it has.
B. Endothermic reaction and +H
These two terms are at par with each other. An endothermic reaction is one in which heat is absorbed from the surroundings. It has a positive value for the heat content i.e the enthalpy is positive and thus H is positive.
C. Exothermic reaction and -H
An exothermic reaction is one in which heat is released to the environment. It usually has a negative value for the enthalpy and thus the value of H is negative.
D. High energy and High Stability
These two terms are not at par. When an entity has or is of high energy, it is usually unstable. An entity at a higher energy level will not be stable until it goes to a lower level of energy.
Thus higher energy level is associated with lesser stability while lower energy levels are associated with higher stability. The lesser the energy of an entity, the higher its stability.
This makes the option our answer.
What is the pH of a weak acid that is 0.2% ionized in a 0.2 M solution?
Answer:
pH=3.40
Explanation:
For this question, we can start with the general ionization reaction of a general acid:
[tex]HA~<->~A^-~+~H^+[/tex]
The acids can produce the hydronium ion ([tex]H^+[/tex]). If we can to calculate the pH we have to use the equation:
[tex]pH=-Log[H^+][/tex]
So, if we want to calculate the pH value we have to know the concentration of the hydronium ion. For this, we can check the percentage of ionization. If we have 0.2 % of ionization, we will have only 0.2 % of hydronium ions from the initial concentration. In other words, we can calculate the concentration of [tex]H^+[/tex], if we do the 0.2% of the initial concentration, so:
[tex]0.2~M*\frac{0.2}{100}~=~0.0004~M[/tex]
With the concentration we can calculate the pH:
[tex]pH=-Log[0.0004~M]~=~3.40[/tex]
The pH value is 3.40
I hope it helps!
A 1.00-mole sample of C6H12O6 was placed in a vat with 100 g of yeast. If 32.3 grams of C2H5OH was obtained, what was the percent yield of C2H5OH?
Answer:
y = 35.06 %.
Explanation:
The reaction of fermentation is:
C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (1)
From the reaction (1) we have that 1 mol of C₆H₁₂O₆ produces 2 moles of C₂H₅OH, then the number of moles of C₂H₅OH is:
[tex]n = \frac{2 moles C_{2}H_{5}OH}{1 mol C_{6}H_{12}O_{6}}*1 mol C_{6}H_{12}O_{6} = 2 moles C_{2}H_{5}OH[/tex]
Now, we need to find the mass of C₂H₅OH:
[tex]m = n*M = 2 moles*46.07 g/mol = 92.14 g[/tex]
Finally, the percent yield of C₂H₅OH is:
[tex] \% = \frac{32.3 g}{92.14 g}*100 = 35.06 \% [/tex]
Therefore, the percent yield of C₂H₅OH is 35.06 %.
I hope it helps you!
The percent yield of C2H5OH should be 35.06% also it have the 1.00 moles.
Calculation of the percent yield:Since
The reaction of fermentation should be
C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (1)
Here 1 mol of C₆H₁₂O₆ generated 2 moles of C₂H₅OH, so the number of moles of C₂H₅OH should be
= 2 moles / 1mole * 1 mole
= 2 moles C₂H₅OH
So here the percent yield should be
= 32.3 / (2 * 4607)
= 32.3 / 92.14
= 35.06%
Hence, The percent yield of C2H5OH should be 35.06% also it have the 1.00 moles.
Learn more about moles here: https://brainly.com/question/19669595
What is a substance?
ASAPPP
Answer:
A particular kind of matter
Explanation:
Write the equality and conversion factors, and identify the numbers as exact or give the number of significant figures for which of the following:A. The Daily Value (DV) for iodine is 150 mcg.B. The nitrate level in well water was 32 ppm.C. Gold jewelary contains 58% gold by mass.D. The price of a litre of milk is $1.65.