aused by the weight of the huge numbers of air molecules that make up the atmosphere. ... When air pressure is low, air flows together and then upward where it converges, rising, cooling, and forming clouds.
Answer:
Explanation:
The weather events happening in an area are controlled by changes in air pressure. Air pressure is caused by the weight of the huge numbers of air molecules that make up the atmosphere. ... When air pressure is low, air flows together and then upward where it converges, rising, cooling, and forming clouds.
A 0.500-g sample containing Na2CO3 plus inert matter is analyzed by adding 50.0 mL of 0.100 M HCl, a slight excess, boiling to remove CO2, and then back-titrating the excess acid with 0.100 M NaOH. If 5.6 mL NaOH is required for the back-titration, what is the percent Na2CO3 in the sample?
The percentage by mass of Na2CO3 in the sample is 48%.
The equation of the reaction of Na2CO3 with HCl;
Na2CO3(aq) + 2HCl(aq) ------> 2NaCl(aq) + H2O(l) + CO2(g)
Since the HCl is in excess, the excess is back titrated with NaOH as follows;
NaOH (aq) + HCl(aq) ---->NaCl(aq) + H2O(l)
Number of moles of HCl added = 0.100 M × 50/1000 L = 0.005 moles
Number of moles of NaOH added = 5.6/1000 × 0.100 M = 0.00056 moles
Since the reaction of NaOH and NaOH is 1:1, 0.00056 moles of HCl reacted with excess HCl.
Amount of HCl that reacted with Na2CO3 = 0.005 moles - 0.00056 moles = 0.0044 moles
Now;
1 mole of Na2CO3 reacts with 2 moles of HCl
x moles of Na2CO3 reacts with 0.0044 moles of HCl
x = 1 mole × 0.0044 moles / 2 moles
x = 0.0022 moles
Mass of Na2CO3 reacted = 0.0022 moles × 106 g/mol = 0.24 g
Percentage of Na2CO3 in the sample = 0.24 g/ 0.500-g × 100/1 = 48%
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Explain in terms of chemical reactivity why the elements in group 18 on the modern periodic table were not identified by Mendeleev's at that time
Answer:
elements tend not to react with other elements, there were no oxide compounds for Mendeleev to study. –Group 18 elements are generally unreactive. sodium ion is smaller because the sodium atom lost one electron. –An Na+ ion is smaller because it has one fewer electron shell.
Explanation:
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Bill sets up an experiment to determine and predict the velocity of a marble at the end of a track. He uses an electronic balance to weigh the marble. He then places the marble at the top of the track and releases it. Artie uses the time it takes the marble to pass through a photogate at the bottom of the track to calculate the velocity of the marble. ill notes that his prediction is significantly higher than his calculated velocity. Which error explains this difference? A) Bill forgot to account for friction. B) Bill forgot to zero the balance and found a weight for the marble that was too low. C) Bill weighed the marble in a weighing dish and failed to account for the mass of the weighing dish. D) Bill didn't position the photogate correctly and got the time required for the top of the marble to pass through, rather than reach the middle.
Answer:
A
Explanation:
USATestPrep
how many grams are in 1.35 moles of NH3
list 2 sources of waste water
Answer:
residential and domestic sources.
Explanation:
Which of the following expresses the value 300,000,000 in correct scientific notation?
Group of answer choices
3 x 108
0.3 x 10-9
3 x 10-8
0.3 x 109
Answer:
3 x 10^8
Explanation:
A team of scientists is working to find the boiling point of a liquid at very low pressure. After three trials, the team has an average
of 12.3°C. An additional trial gives a result of 13.1°C. Which statement is a reasonable conclusion that can be drawn from this
result? (1 point)
O The original average should be thrown out because it could not be confirmed by new results.
O More data should be collected because the first three trials appear to be wrong.
O The original average should be used because it came from three results, not just one.
O More data should be collected to get a more reliable average.
Since it is conventional in science to use an average not just a single result, the original average should be used because it came from three results, not just one.
The boiling point refers to the temperature when the pressure of the fluid equals the atmospheric pressure. Hence, boiling occurs at atmospheric pressure.
In scientific experiments, it is common to conduct experiments more than once and obtain an average value for the measurement. In this case, the original average should be used because it came from three results, not just one.
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Passive prostheses are:
- self-regulated
- easily corroded
- made of nanotubes
- self-powered
Passive prostheses are self-regulating, as shown in the first answer option.
We can arrive at this answer because:
Passive prostheses are devices used to replace parts of the body that were lost by an incident.These prostheses are very useful to establish balance or the aesthetics of the body, but they have no articulations and no movement mechanism, being static.This limitation allows passive prostheses not to need external regulation and to be self-regulated by fitting the body parts.
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Answer:
self-powered.
Acid hydrolysis of N-methylbutyramide in water and hydrochloric acid with heat produces______________________________.
a. Butyric acid and methylammonium chloride.
b. Butanoic acid and ammonium chloride.
c. Butanoate and methylamine.
Answer:
A- Butyric acid and methylammonium chloride.
Explanation:
Symbol of elements.
Explanation:
Gold Au
Copper Cu
Iron Fe
Magnesium Mg
Hydrogen H
Helium He
Mercury Hg
Iodine I
Explain why the total mass of carbon must be decreasing in a different step of the slow carbon cycle based on the increase in atmospheric CO2.
Total mass of carbon must be decreasing in different step of carbon cycle because matter is conserved in the processes and reactions of carbon cycle. Carbon is a matter and it is the major constituent of living organisms.
Carbon cycle refers to processes where carbon move from the atmosphere to the biosphere and Earth and then back to the atmosphere.
It involves processes of using and reusing carbon again and again and it's conservation.
Carbon is an organic matter found in living organisms and total mass of carbon reduces because it is a matter that is conserved.
Carbon is released from that atmosphere, use for photosynthesis, plants and animals consume the plants. They defecate , respirate and carbondioxide is released during respiration.
Therefore,Total mass of carbon must be decreasing in different step of carbon cycle because because matter is conserved in the processes and reactions of carbon cycle. Carbon is a matter and it is the major constituent of living organisms.
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What do these white-precipitate reactions have in common? (choose the best
answer)
They all have a chromate (Cro, 2) ion.
They all have a chloride ( Cl-1) ion.
They all made the same color.
They all have a barium (Bat
+2) cation
Answer:
They all have a choloride(CI-1) ion
Explanation:
Consider the reaction where barium sulfate can be prepared from 2.76 mol of sodium sulfate and excess barium acetate. Sodium acetate is the other product
1.write the balanced MOLECULAR reaction.
2.write the balanced total ionic equation.
3.write the balanced net ionic equation.
Answer:
1. Na2SO4(aq)+C4H6BaO4(aq) --> BaSO4(s) + 2C2H3NaO2(aq)
2. 2Na^+1(aq) + SO4^-2(aq) + 4C^+4(aq) + 6H^+1(aq) + Ba^-2(aq) + 4O^-2(aq) --> BaSO4(s) + 2C^-4(aq) + 2H^+1(aq) + 3Na^+1(aq) + 2O^-2(aq)
3. Ba^+2(aq) + SO4^-2(aq) --> BaSO4(s)
Explanation:
NEED HELP ASAP WILL GIVE BRAINLIEST
Answer:
2.83
Explanation:
Molar concentration (mol/litre) = mass/molar mass × 1000/volume(in ml)
0.849 = mass/60.09 × 1000/55.5
mass = (0.849 × 60.09 × 55.5)/1000
= 2.8314
To 2 decimal places = 2.83
What is the formula unit for an ionic compound?
Answer:
empirical formula
what is the true of lewis base
Answer: To answer your question of what is true of a lewis base, it is true that a lewis base donates electron pairs.
Explanation: A Lewis base is any substance, such as the OH- ion, that can donate a pair of nonbonding electrons. A Lewis base is therefore an electron-pair donor.
a fisherman in a boat is drinking a of hot coffee. the large lake below his boat is full of cold water. which statement is an accurate comparison of the lake water and the coffee?
Answer:
see below
Explanation:
The lake will have more total thermal energy but the particles in the coffee will be moving faster.
A comparison of hot coffee and cold lake is, the heat from the coffee will be absorbed by the cold lake through convection method of heat transfer.
Conservation of energy
The principle of conservation of energy states that the total energy of an isolated system is always conserved.
Heat lost by the hot coffee = Heat absorbed by the cold lake
Heat transfer processHeat from the coffee will be absorbed by the cold lake through convection method of heat transfer.
Thus, a comparison of hot coffee and cold lake is, the heat from the coffee will be absorbed by the cold lake through convection method of heat transfer.
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Identify one cause of the loss of forests that is not intentional.
Answer:
Natural causes are unintentional.
Explanation:
An example would be a wildfire. This natural disaster spreads quickly, especially in forests where wood burns easily. Destroying forests through burning causes nutrients to get depleted, and organisms die.
A photon is BEST described as _?
A. A subatomic particle of light
B. A negatively charged subatomic particle
C. A particle larger than an atom
D. A particle inside an atom
A student is studying the boiling points of six different liquids and finds results with consistently higher boiling points than what research would suggest. Which option describes a likely cause?
Answer:
Large molecules tend to have greater boiling points because the London dispersion forces are stronger within.
Explanation:
14. pH value are basic are greater than what number while acids are have a pH less than
this value?
Answer:
Less than 7 ph value are acidic. Greater than 7 ph value are basic.
The model below shows the equation that represents how hydrogen and oxygen combine to form water. In this chemical reaction, the reactants
are hydrogen gas and oxygen gas.
2H2 + O2 + 2H2O
True
False
Answer:
true
Explanation:
because they are balance
Determine the frequency of light with a wavelength of 2.672 x 10^-7cm
Answer:
Determine the frequency of light with a wavelength of 2.775⋅10−7 cm. Answer in units of Hz?❤
what takes place when the pollen grains are transferred to the stigma of the same flower with the help of pollinators
Answer:
self-pollination.
Explanation:
When the pollen of the flower is transferred to the stigma of the same flower, it is called self-pollination. Cross-pollination occurs when pollen is transferred from one flower to another flower on the same plant, or another plant.
Where do you put the value for how many of each atom you need?
Multiple choice
A. Below and before the symbol.
B. Above and after the symbol.
C. Below and after the symbol.
D. Above and before the symbol.
Answer:A
Explanation
:
Why do scientists use the scientific method?
A. It helps them do research that other scientists can understand.
B. It helps them ask questions that affect as many people as
possible.
C. It helps them make sure a certain question has not been asked
before.
OD. It helps them determine whether an idea is supported by evidence.
Help
Answer:
DExplanation:
It helps determine whether an idea is supported by evidencehope it helps please follow because I don't have any followers I have 0 followersWhat does lowercase v represent in this formula?
what is an adaptive organ of duck
Answer:
The adaptive organ of duck is webbed feet.
Explanation:
Duck's webbed feet are designed like paddles to provide more surface area to help them swim.
the webbed feet
Explanation:
97.3 FM radio station broadcasts electromagnetic waves at a frequency of 97.3 megahertz (97.6 x 106 Hz). These radio waves travel at a
speed of 3.00 x 108 m/s. What is the wavelength of these radio waves?
*Include your units!
Round your answer to the nearest hundredth (2 decimal places).
The wavelength of the electromagnetic wave at the given frequency is 3.07 meters.
Given the following data:
Frequency =[tex]97.6 \times 10^6\; Hz[/tex]Speed = [tex]3 \times 10^8\;m/s[/tex]To determine the wavelength of the electromagnetic wave at the given frequency:
Mathematically, the wavelength of an electromagnetic wave is calculated by using the formula;
[tex]Wavelength = \frac{Speed }{frequency}[/tex]
Substituting the given parameters into the formula, we have;
[tex]Wavelength = \frac{3 \times 10^8}{97.6\times 10^{6}}[/tex]
Wavelength = 3.07 meters.
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major classification of crude product
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Explanation:
Crude is classified, based on density, as light, medium, heavy, or extra heavy. It can also be classified, based on sulfur content, into a sour and sweet category.