Answer:
3 moles of calcium oxide are formed
Explanation:
Based on the reaction of Calcium Ca, with oxygen, O₂, to produce calcium oxide, CaO is:
2Ca + O₂ → 2CaO
where 2 moles of calcium produce 2 moles of Calcium oxide.
That means, if 3 moles of Ca react in presence of oxygen:
3 moles of calcium oxide are formed
The division of Earth’s history into smaller units makes up the ____.
Answer:
geologic time scale
hope this helps
have a good day :)
Explanation:
The atomic model that describes an atom as a spherical object containing a certain number of electrons trapped in a mass of positive charge is often called the ___________ model.
help
i need help with this pls
I know it’s E and A
Explanation: did you count it’s exactly 28, also the electrons are not visible.
Ps: I’m in 5th grade, what grade is this, if my suggestion was correct then holy crackers.
why is hydrogen a nonmetal,usually placed with group 1 elements in the periodic table even though it does not show a metallic property like the alkalietals?
Periodic table has been divided into three, one is metal, second is non metal and third metalloid. Therefore, hydrogen is considered as non metal.
What is metal?Metals are those elements which is hard, conduct electricity, ductile, lustrous and malleable.
Lets take property
1.Since metals have free electrons that's why they can conduct electricity
2. Since atoms in metals are very closely packed in a definite crystal so Aluminium is solid. It is not brittle that is it can not be broken down easily
3. It does not react with water.
4.It is denser than water hence it sink in water.
Since hydrogen has only 1 electron in its outermost shell, to complete its duet and gain stability, hydrogen has to gain 1 electron just like halogen. So, on this basis hydrogen is considered as non metal.
Therefore, hydrogen is considered as non metal.
Learn more about the metals, here:
https://brainly.com/question/27859211
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Which of these is not a characteristic of sponges?
lack a backbone
lack a brain
stationary
have a nervous system
The following graph shows a decay chain. Which part of the decay will take the most time? the decay of U-238 to Th-234, the decay of Th-234 to Ra-226, the decay of Ra-226 to Po-214, the decay of Po-214 to Pb-206
A- the decay of U-238 to Th-234
right on edge 2021
Answer:
A) the decay of U-238 to Th-234
:)
Explanation:
Is oil a reasonable energy source? Why or why not?
Answer:
No, it is not.
Explanation:
Oil is a non-renewable source of energy. ... Burning oil can pollute the air. Much of our oil has to be imported and it is becoming more and more expensive as reserves reduce and imports increase. Producing electricity from crude oil is expensive compared to other fossil fuels such as coal or gas.
*You Can put this in your own words
Compare How does the horse's average speed from 60 s to 120 s compare to its average speed from 120 s to 180 s?
Answer:
Explanation:
To compare the average speed, we would need some parameters which you clearly didn't state in your question. However, permit me to manufacture some from thin air.
The formula for average speed is given as
Speed = distance / time
From the question, we have the time, but not the distance moved by the horse. Now, assuming the horse moves a distance of 60 meters, then we can say,
Speed = 60 / 60
Where the difference between the two time, t = 120 - 60 = 180 - 120 = 60
So, from my hypothesized example, the average speed of the horse is 1 m/s
Speed is the rate of change of position expressed as _____ traveled per unit of time. A. direction B. meter C. displacement D. distance... Help!!!
Answer:
Speed is the rate of change of position expressed as distance travelled per unit of time .
Explanation:
what are protons, what is their charge, and where they located?
There are 1 1/2 times the amount of
we need on the planet today
Review the chart of all the domesticated rabbits. The different types of rabbits are listed by their scientific names. If you were a
rabbit breeder, which rabbits could you breed to produce fertile offspring? Explain.
A)
All of the rabbits listed. They are all rabbits.
B)
None of these rabbits. They are all different species.
C)
Any of the cottontail rabbits They are the same species.
D)
Any of the rabbits on the same branch in the chart because that means
they are closely related.
Answer: None of these rabbits listed. they are all different species
Explanation:
I got it right on usatestprep
What is the measure of the indicated angle? 37∘ 53∘ 180∘ 127∘
Answer:
53∘
plz mark me as brainliest.
what can you infer about aspirin’s ester group?
A. It provides aspirin’s pain-killing ability.
B. It makes the compound more digestible.
C. It reduces fevers.
It's B
Answer:
Option B, aspirin’s ester group provides greater digestibility to aspirin
Explanation:
Aspirin ester group has three parts
carboxylic acid functional group (R-COOH) ester functional group (R-O-CO-R') aromatic group (benzene ring)Aspirin is a weak acid and hence it cannot dissolve in water readily. The reaction of Aspirin ester group with water is as follows -
aspirin
(acetylsalicylic acid) + water → salicylic acid + acetic acid
(ethanoic acid)
Aspirin passes through the stomach and remains unchanged until it reaches the intestine where it hydrolyses ester to form the active compound.
how has the study of fossil rocks evolved over time? (personal answer)
Answer:
When an organism dies, it is usually destroyed by other forms of life and by weathering processes. On rare occasions some body parts—particularly hard ones such as shells, teeth, or bones—are preserved by being buried in mud or protected in some other way from predators and weather. Eventually, they may become petrified and preserved indefinitely with the rocks in which they are embedded. Methods such as radiometric dating—measuring the amounts of natural radioactive atoms that remain in certain minerals to determine the elapsed time since they were constituted—make it possible to estimate the time period when the rocks, and the fossils associated with them.
What of reaction is Zn + H2S =ZnS + H2
In describing weather completely, it is important to include, among other aspects, air pressure, precipitation, and humidity. Which of the following statements is false?
Wind is the movement of air that results from differences in air pressure.
Precipitation is a form of water that falls to Earth’s surface from the clouds.
Air typically moves from areas of lower pressure to areas of higher pressure.
When the temperature of the air cools to the dew point, the air is saturated, and water droplets will form.
Answer:
The false statement is - Air typically moves from areas of lower pressure to areas of higher pressure.
Explanation:
The wind is the air movement that takes place due to pressure differences or the temperature difference of air. Air moves from the higher pressure area to the lower pressure area. The more the difference will be the faster the air will move to a low-pressure area.
Precipitation is a form of water that falls from clouds to earth, it can be rainfall, snow and other forms. Dew is one of the forms that occur when the air cools down to the dew point and form droplets.
Answer:
Air typically moves from areas of lower pressure to areas of higher pressure.
Explanation:
What is the mole ratio of magnesium carbonate to magnesium oxide? MgCO3 →MgO+CO2
a)3:2 b) 1:3 c) 1:1 d) 1:2 e) 2:3
Answer:
d)1:2
Explanation:
PLEASE HELP DUE IN 20 MINUTES Find the empirical formula for the following problem. Remember to show your work if you want
to earn credit.
1. One mole of an unknown compound has 36.0 g of carbon and 6.0 g of hydrogen. What
is the empirical formula of the unknown compound? (Hint: You will want to reduce to find
the empirical formula)
Given: Carbon: 36.0 grams
1 mol C = 12.0 g
Hydrogen: 6.0 g
1 mol H = 1.0 g
Unknown: empirical formula
Solve:
Answer:
CH2
Explanation:
The empirical formula is the simplest formula of a chemical compound. It shows the ratio in which constituent atoms are combined in the compound.
To obtain the empirical formula, we divide the given mass of each element by the relative atomic mass of that element.
C- 36.0 g/12.0 g H- 6.0g/1.0g
C- 3 H-6
Divide through by the lowest ratio;
C-3/3 H- 6/3
C-1 H-2
Hence the empirical formula of the compound is
CH2
How many calories of heat were added to 167.9 g of water to raise its temperature from 25oC to 55oC?
Answer:
Q = 5036.9 calories
Explanation:
Given that,
Mass, m = 167.9 g
The temperature raises from 25°C to 55°C.
The specific heat of water,c = 4.184 J/g °C
We need to find the heat added to water. We know that,
[tex]Q=mc\Delta T\\\\=167.9 \times 4.184\times (55-25)\\\\=21074.8\ J[/tex]
or
Q = 5036.9 calories
So, 5036.9 calories of heat is added.
How does a nuclear power plant create electricity?*
A: A nuclear reaction burns fuel
B: A nuclear reaction caused water to flow, which is then what creates electricity
C: A nuclear reaction creates heat which is applied to water to create steam
D: A nuclear reaction creates an electrical current
Answer:
CExplanation:
Answer:
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*At 25 °C, gas in a rigid cylinder with a movable piston has a volume of 145 mL and a pressure of 125 atm. Then, the gas is compressed to a volume of 80mL What is the new pressure of the gas if the temperature is at 30°C?
Answer:
Pressure will increase by the direct ratio of the volume change. Therefore, since volume changes from 145 to 80, pressure will go up by the ratio change 145÷80 times the original pressure 125 kPa. Sure, you can use the more complicated gas law equation PV = nRT but we are only varying volume so the question boils down to the change in one simple variable.
Putting them together we have: 145÷80 x 125 = 226.5625 or just 226 kPa since the accuracy of the figures and the equation are not great.
find the ratio of the initial volume to final volume if the temperature of the gas is changed from 27°C to 127°C at constant pressure.
Answer: The ratio of the initial volume to final volume for the given gas is 27 to 127 L at constant pressure.
Explanation:
Given: [tex]T_{1} = 27^{o}C[/tex]
[tex]T_{2} = 127^{o}C[/tex]
According to Charle's law, for an ideal gas pressure is directly proportional to the temperature at constant pressure.
So, formula used to calculate the ratio of the initial volume to final volume is as follows.
[tex]\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}\\\frac{V_{1}}{V_{2}} = \frac{T_{1}}{T_{2}}\\\frac{V_{1}}{V_{2}} = \frac{27}{127}[/tex]
Hence, we can conclude that the ratio of the initial volume to final volume for the given gas is 27 to 127 L at constant pressure.
What is the total volume of water that you have if you calculated that it
weighs 180g?
URGENT ! PLEASE ANSWER QUICKLY
Calculate the volume of a NaCl solution that would contain 5.0 g of NaCl and have a molarity of 4.8 M.
Calculate the pH for a solution with a 4.6 x 10-9 M hydronium concentration.
Answer:If we dissolve NaF in water, we get the following equilibrium:
text{F}^-(aq)+text{H}_2text{O}(l) rightleftarrows text{HF}(aq)+text{OH}^-(aq)
The pH of the resulting solution can be determined if the K_b of the fluoride ion is known.
20.0 g of sodium fluoride is dissolve in enough water to make 500.0 mL of solution. Calculate the pH of the solution. The K_b of the fluoride ion is 1.4 × 10 −11 .
Step 1: List the known values and plan the problem.
Known
mass NaF = 20.0 g
molar mass NaF = 41.99 g/mol
volume solution = 0.500 L
K_b of F – = 1.4 × 10 −11
Unknown
pH of solution = ?
The molarity of the F − solution can be calculated from the mass, molar mass, and solution volume. Since NaF completely dissociates, the molarity of the NaF is equal to the molarity of the F − ion. An ICE Table (below) can be used to calculate the concentration of OH − produced and then the pH of the solution.
Explanation:
Answer:
not sure if this is 100% correct but this is what i got first question: molarity=mol/L 5g*1mol/58.44g=5/58.44 =0.085558mol 4.8m=0.085558/L L=0.0178
jiujuan avatar
second question: pH = - log [H3O+] pH= -log [4.6*10^-9] = 8.33724216
Explanation:
(b) Potassium and sodium are kept in dark reagent bottles filled with paraffin oil.
Explain why.
Answer:
these metals are stored in kerosene because kerosene contains no water and protects these metals from being exposed to any moisture in the air that would cause these metals to react, potentially violently.
Using the ideal gas law, what will be the volume occupied by 1.46 moles of helium at
0.982 atmospheres and 13.0°C? (R = 0.0821 L'atm/mol-K)
Answer:
34.91 L
Explanation:
Ideal gas law -> PV=nRT
convert C to K -> 13+273 = 286
plug numbers in
(.982)V=(1.46)(.0821)(286)
V = 34.91 L
When more gas particles are added to the same space, how will the behavior change?
Answer:
The particles move very fast and collide into one another, causing them to diffuse, or spread out, until they are evenly distributed throughout the volume of the container. When more gas particles enter a container, there is less space for the particles to spread out, and they become compressed.
Explanation:
a gas measured a volume 100 mL under pressure of 740 mmHg. What would the volume be under a pressure of 780 mmHg with constant temperature
Answer:
94.87 mLExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we're finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
We have
[tex]V_2 = \frac{100 \times 740}{780} = \frac{74000}{780} \\ = 94.8717...[/tex]
We have the final answer as
94.87 mLHope this helps you
Which two moon phases can occur while the
relative positions of the sun, Earth, and moon
form a straight line?
Answer:
its the lunar and solar eclipse
Explanation:
the solar eclipse happens when the moon is in between the sun and earth