Answer:
U=q+w
=5.00×10^2 +5.00×10^2
=2.5×10^5 kJ
What will be the pH of a buffer solution containing an acid of pKa7.5, with an acid concentration exactly one fourth of that of the conjugate base
Answer: pH of buffer solution is 8.1
Explanation:
The formula for the Henderson–Hasselbalch equation is:
[tex]pH=pK_a+\log\frac{[A^-]}{[HA]}[/tex]
[tex]pH[/tex] is the concentration of [tex][H^+][/tex]
[tex]pK_a[/tex] is the acid dissociation constant,
[tex]A^-[/tex] and [tex]HA[/tex] are concentrations of the conjugate base and starting acid.
Putting in the values we get:
[tex]pH=7.5+\log\frac{x}{\frac{x}{4}}[/tex]
[tex]pH=8.1[/tex]
Thus pH of buffer solution is 8.1
Determine the amount of current going through a 50ohms; resistor with a voltage of 120 v
Answer:
98.356 ohms is the answer
Which nitrogenous base is NOT found in DNA? *
A. cytosine
B. guanine
C. uracil
D. adenine
Answer:
c. uracil
Explanation:
uracil is not found in DNA. the missing base would be thymine
Atoms with 5 or more valence electrons tend to form __________________ ions, called _________.
Answer:
positively-charged cations
Explanation:
hope this helps! :)
What is true about renewable resources?
They are rare on Earth.
They can be replenished fast.
They can be replenished over millions of years.
They are very abundant on Earth.
They can be replenished fast.
How much energy ( in joule ) does the Sun emit in one day (24 hours)? I've previously answered with 3.32, but it was incorrect. Please help thanks.
It is about 3.86 which is 10⁶⁶ watts
Answer:
410 quintillion Joules or 430,000,000,000,000,000,000 Joules
Question 7 point
What is the name of the covalent compound with the formula P2N3?
8. If 134 L of Nitrogen gas at STP is combined with 99 L of Chlorine gas at STP,
Which is the limiting reactant?
N2 + Cl2 → NCI3
.
Answer:
Cl₂ is the limiting reactant.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
N₂ + 3Cl₂ —> 2NCl₃
From the balanced equation above,
1 L of N₂ reacted with 3 L of Cl₂.
Finally, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
1 L of N₂ reacted with 3 L of Cl₂.
Therefore, 134 L of N₂ will react with = 134 × 3 = 402 L of Cl₂.
From the calculation made above, we can see that a higher volume (i.e 402 L) of Cl₂ than what was given (i.e 99 L) is needed to react completely with 134 L of N₂.
Therefore, Cl₂ is the limiting reactant and N₂ is the excess reactant.
Calculate the ratio of the effusion ratesbetween chlorine gas (Cl2, molar mass = 71 g/mol) and iodine gas(I2, molar mass = 254 g/mol).
a)0.280
b)1.89
c)3.58
d)8.43
Answer:
d is the correct answer
Explanation:
Which layer of the Earth includes the crust? a atmosphere b hydrosphere c asthenosphere d lithosphere
Answer:
D
Explanation:
Hope that helps :)
Which of the following environments is most likely to have days with a relative humidity of less than 10% (ten percent)?
a desert
a swamp
a rainforest
a deciduous forest
Answer:
Desert
Explanation:
Desert barely have any water therefore they can barely produce any amount of humidity
I a doing an exam in science pls help.
What type of energy comes from the motion of tiny particles of matter?
Answer:
heat
Explanation:
Answer:
Thermal Energy
Explanation:
In a sample of neon, carbon, and oxygen gas, the total pressure is 9 atm.
The partial pressure of neon is 2 atm and the partial pressure of oxygen is 2
atm. What is the partial pressure of carbon?
9 atm
3 atm
5 atm
4 atm
Answer:
5 atm
Explanation:
add boh partial pressures and subtract from total pressure
The formula for chromium (vi)bromate
Answer: The formula of chromium fluoride is CFr2.
A piece of unknown solid substance weighs 437.2 g, and requires 8460 J to increase its temperature from 19.3 °C to 68.9 °C.What is the specific heat of the substance?
Answer:
0.3832
Explanation:
Givens
m = 437.2 grams
c = ?
delta t = 69.8 - 19.3
H = 8460 J
Formula
H = m*c*Δt
Solution
8460 = 437.2 * c * (69.8 - 19.3)
8460 = 437.2 * c * 50.5
8460 = 22078.6 * c
c = 8460 / 22078,6
c = .3832 J / (oC * gr)
Arrange the following substance into acid,base and neutral. sodium chloride, tomato juice, vinegar,sea water,bicorbonate of sodium
Answer:
sodium chloride: neutral.
tomato juice: acid.
vinegar: acid.
sea water: base.
bicarbonate of sodium: base.
Explanation:
Hello there!
In this case, in agreement to the definition of the pH, as the measure of the acidity and basicity of a substance; it is important to recall that pH's below 7 stand for acidic substances and pH's above 7 stand for basic substances, whereas a pH of 7 defines a neutral one. In such a way, given the pH's of the given substances, 7, 4.05 to 4.65, around 2.5, about 8.1 and about 8.3 respectively for sodium chloride, tomato juice, vinegar, sea water, bicarbonate of sodium, it is possible to assert:
sodium chloride: neutral.
tomato juice: acid.
vinegar: acid.
sea water: base.
bicarbonate of sodium: base.
Best regards!
HELP ASAP PLEASE!!! :)
Answer:
Alkane
Explanation:
Alkenes have CH in their condensed formulas and alkynes have C in their condensed formulas. There are only CH3 and CH2 so it's an alkane.
What is the volume of .80 g of O2 gas at STP?
Answer:0.56L
Explanation:Molar mass of O2=32
N=0.8/32
N=0.025
V=0.025 x 22.4=0.56L
Which of the following best describes the type of particle found in the cloud around an atom’s nucleus?
It has a negative charge and much less mass than a neutron
It has a negative charge and about the same mass as a neutron.
It has a negative charge and about the same mass as a neutron.
It has a positive charge and about the same mass as a neutron.
8. How much heat will be released when
18.6 g of hydrogen reacts with excess O2
according to the following equation?
Answer:
15 is it
Explanation:
Which salt preparation uses a burette and a pipette
potassium chloride from potassium hydroxide and hydrochloric acid
Why do scientists think that liquid water might have once existed on Mars?
Answer: The discovery of three buried lakes. Scientists think that a long time ago there were lakes and rivers, etc on Mars. Now of course, you can't see any visible water sources on the surface.
Answer:
Almost all water on Mars today exists as ice, though it also exists in small quantities as vapor in the atmosphere.[5] What was thought to be low-volume liquid brines in shallow Martian soil, also called recurrent slope lineae may be grains of flowing sand and dust slipping downhill to make dark streaks.The only place where water ice is visible at the surface is at the north polar ice cap. Abundant water ice is also present beneath the permanent carbon dioxide ice cap at the Martian south pole and in the shallow subsurface at more temperate conditions. More than 5 million km3 of ice have been detected at or near the surface of Mars, enough to cover the whole planet to a depth of 35 meters. Even more ice is likely to be locked away in the deep subsurface.
Some liquid water may occur transiently on the Martian surface today, but limited to traces of dissolved moisture from the atmosphere and thin films, which are challenging environments for known life. No large standing bodies of liquid water exist on the planet's surface, because the atmospheric pressure there averages just 600 pascals , a figure slightly below the vapor pressure of water at its melting point; under average Martian conditions, pure water on the Martian surface would freeze or, if heated to above the melting point, would sublime to vapor. Before about 3.8 billion years ago, Mars may have had a denser atmosphere and higher surface temperatures, allowing vast amounts of liquid water on the surface, possibly including a large ocean that may have covered one-third of the planet.Water has also apparently flowed across the surface for short periods at various intervals more recently in Mars' history. Aeolis Palus in Gale Crater, explored by the Curiosity rover, is the geological remains of an ancient freshwater lake that could have been a hospitable environment for microbial life.Many lines of evidence indicate that water ice is abundant on Mars and it has played a significant role in the planet's geologic history.The present-day inventory of water on Mars can be estimated from spacecraft images, remote sensing techniques (spectroscopic measurements, radar, etc.), and surface investigations from landers and rovers.Geologic evidence of past water includes enormous outflow channels carved by floods, ancient river valley networks, deltas and lakebeds,and the detection of rocks and minerals on the surface that could only have formed in liquid water. Numerous geomorphic features suggest the presence of ground ice (permafrost)and the movement of ice in glaciers, both in the recent past and present. Gullies and slope lineae along cliffs and crater walls suggest that flowing water continues to shape the surface of Mars, although to a far lesser degree than in the ancient past.Although the surface of Mars was periodically wet and could have been hospitable to microbial life billions of years ago, the current environment at the surface is dry and subfreezing, probably presenting an insurmountable obstacle for living organisms. In addition, Mars lacks a thick atmosphere, ozone layer, and magnetic field, allowing solar and cosmic radiation to strike the surface unimpeded. The damaging effects of ionizing radiation on cellular structure is another one of the prime limiting factors on the survival of life on the surface. Therefore, the best potential locations for discovering life on Mars may be in subsurface environments. Large amounts of underground ice have been found on Mars; the volume of water detected is equivalent to the volume of water in Lake Superior. In 2018, scientists reported the discovery of a subglacial lake on Mars, 1.5 km (0.93 mi) below the southern polar ice cap, with a horizontal extent of about 20 km (12 mi), the first known stable body of liquid water on the planet.Understanding the extent and situation of water on Mars is vital to assess the planet’s potential for harboring life and for providing usable resources for future human exploration. For this reason, "Follow the Water" was the science theme of NASA's Mars Exploration Program (MEP) in the first decade of the 21st century. NASA and ESA missions including 2001 Mars Odyssey, Mars Express, Mars Exploration Rovers (MERs), Mars Reconnaissance Orbiter (MRO), and Mars Phoenix lander have provided information about water's abundance and distribution on Mars.Mars Odyssey, Mars Express, MRO, and Mars Science Lander Curiosity rover are still operating, and discoveries continue to be made.
2 Nal + Pb(NO3)2
2 NaNO3 + Pb12
How many oxygen atoms are on the left side of the equation?
there are 6 O atoms suvdjwndje
Estimate the solubility of barium fluoride, BaF2, in a 0.100 M solution of barium nitrate, Ba(NO3)2, given that the K sp of BaF2 is 2.45×10-5.
A)7.83×10-3 M
B)1.57×10-2 M
C)7.83×10-4 M
D)2.45×10-4 M
Answer:
A) 7.83 x 10^-3 M
Explanation:
7.83 x 10⁻³ M is the solubility of barium fluoride, BaF[tex]_2[/tex], in a 0.100 M solution of barium nitrate, Ba(NO[tex]_3[/tex])[tex]_2[/tex], given that the K sp of BaF[tex]_2[/tex]is 2.45×10-5. The correct option is option A.
What is solubility?The ability of a material, the solute, to combine with some other substance, the solvent, is known as solubility in chemistry. Insolubility, or the solute's inability to create such a solution, is the opposite attribute. The concentration of a solute inside a saturated solution is typically used to determine how much of a substance is soluble in a certain solvent.
The two compounds are said to be just at solubility equilibrium at this time. There might not be a limit for some solutes or solvents, in which case they two are referred to as "miscible in any quantities." Whereas the solvent is often solid or liquid, the solute may be either a solid, liquid, or gas.
BaF[tex]_2[/tex]=0.100 M
Ba(NO[tex]_3[/tex])[tex]_2[/tex]=0.100 M
K sp of BaF[tex]_2[/tex]=2.45×10⁻⁵
solubility of barium fluoride=2.45×10⁻⁵×0.100 =7.83 x 10⁻³ M
Therefore, the correct option is option A.
To know more about solubility, here:
https://brainly.com/question/14366471
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all metals rust please answer false or true
Answer:
True
Explanation:
All metals do rust but at different rates. Gold, platinum, and silver can rust if but at different rates. It can take time for it to rust, if you clean your metals, it won't rust, it'll take awhile before it rusts if you keep cleaning them.
Hopefully this helps :3 sorry if wrong :( plz mark brainiest if correct :D your bootiful/handsome! Have a great day luv <3
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how many molecules of sodium chloride are in 2.5 moles??
Answer:
1.5x1024
Explanation:
How many moles of hydrogen
are in 3.06 x 10^-3 g of glycine C2H5NO2
Answer:
2.04x10⁻⁴ mol
Explanation:
First we convert 3.06x10⁻³ grams of glycine into moles of glycine, using its molar mass:
3.06x10⁻³ g ÷ 75 g/mol = 4.08x10⁻⁵ mol C₂H₅NO₂In order to calculate the number of hydrogen moles, we multiply the number of glycine moles by 5, as there are 5 hydrogen moles per glycine mol:
4.08x10⁻⁵ mol C₂H₅NO₂ * 5 = 2.04x10⁻⁴ mol HWhy are some resources, like fossils, found in some places and not in others?
Answer:
Because thats where the animal passed away
Explanation:
Calculate the percent composition of C in carbon dioxide.
Answer:
27.27%
Explanation:
What are the benefits of Fluoride?
Answer:
The benefits of Fluoride are rebuild (remineralize) weakened tooth enamel.slow down the loss of minerals from tooth enamel.reverse early signs of tooth decay.prevent the growth of harmful oral bacteria
Answer:
Fluoride is often called nature's cavity fighter and for good reason. Fluoride, a naturally-occurring mineral, helps prevent cavities in children and adults by making the outer surface of your teeth (enamel) more resistant to the acid attacks that cause tooth decay.