Answer:
27.27%
Explanation:
How many moles of NaOH are contained in 56.0 mL of a 2.40 M solution of 1 point
NaOH in water? (**Use only numerical answers with 3 significant figures.
The units are given in the question.)
Your answer
Answer:
1.34 mol
Explanation:
Molarity, which is the molar concentration of a solution, can be calculated by dividing the number of moles (n) by the volume (V).
That is;
Molarity (M) = n/V
According to the information provided in this question;
M = 2.40M
V = 56.0 mL = 56/1000 = 0.056 L
Since molarity = n/V
number of moles = M × V
n = 0.056 × 24
n = 1.34 mol
What is the volume of 0.200 moles of O2 gas at STP?
Answer:
4.48 L O2
Explanation:
At STP, a mole of any gas contains 22.4 liters. Therefore, we simply have to multiply the amount of moles by 22.4
0.2mol O2 ( 22.4 L) = 4.48 L O2
which of the following, when dissolved in water, forms a weak acid.A. HNO3B. HClO4C. HBrD. HClOE. NH3
Answer:
The weak acid is - E. [tex]NH_3[/tex]
Explanation:
Ammonia is a strong base, which in turn make it to be a weak acid.
As, the rest of the options are acid and therefore furnish hydrogen ions when dissolved in water, making them strong acid.
And ammonia dissolves in water to form its conjugate ammonium ion and hydroxide ion, therefore making the solution basic.
Hence, from the given options, the correct option is E. [tex]NH_3[/tex]
The compound which when dissolved in water, forms a weak acid is; Choice E: NH3
According to the question;
we are required to determine which compound forms a weak acid when dissolved in water.Unlike other compounds (HNO3, HClO, HBr, HClO) which dissolve in water to yield H+ ion, Ammonia dissolves in water to form ammonium ion and hydroxide ion, OH-.
In essence, NH3 is a strong base when dissolved in water and consequently, is a weak acid when dissolved in water.
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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:
.35L sample of helium gas is collected at 295 K and 0.98 ATM what volume would this gas occupy at STP
Answer:
0.3857 litres is the answer
Where are electrons found in an atom?
Answer:
outside the nucleus
Explanation:
Help will give brainliest no “click this link”
The longest continuous carbon chain comprises five carbon atoms connected by single bonds, so the root name will be pentane. There is a methyl group (—CH3) attached to carbon 3 (since this molecule is symmetrical, the methyl substituent will always be on carbon 3 regardless of which end you begin counting). Thus, the name of this molecule would be 3-methylpentane.
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
Identify the most and the least basic compound in each of the following sets. Leave the remaining answer in each set blank. a) Sodium acetate: _______ Ammonia: _______ Sodium ethoxide: _______ b) Sodium acetate: _______ Sodium chloroacetate: _______ Sodium fluoroacetate: _______ c) Sodium acetate: _______ Sodium methoxide: _______ Sodium phenoxide:
Answer:
The correct answer is -
a) Sodium acetate: least Ammonia: _______ Sodium ethoxide: most
b) Sodium acetate: most Sodium chloroacetate: _______ Sodium fluoroacetate: least
c) Sodium acetate: least Sodium methoxide: most Sodium phenoxide:
Explanation:
A) In this case the basicity can be found by the stability of the base, Sodium acetate is the most stable base due to resonance stabilization of acetate anion. Sodium acetate is the least basic as the lone pair of electrons involved in the resonance here. An ethoxide ion has more electrons to donate an electron pair easily.
Thus, the correct answer is - Sodium acetate is the least basic while sodium ethoxide is the most basic.
B) Fluroacetate gives a very strong acid and the acetate gives the least strong acid among all three as described in case of a), thus, the most basic is acetate and the least is fluoroacetate.
]C) comparing the acidity of the acids formed by the addition of a proton to the anions is an easy and correct way to find the basicity of compounds.
Acetate ion adds a proton ⇒ acetic acid
methoxide adds a proton ⇒ methanol
phenoxide ion adds proton ⇒ phenol
As it is known that the stronger the acid, the weaker is the conjugate base formed by the loss of the proton.
acetic acid is the strongest acid because it can easily give up its proton to form acetate. Methanol is the weakest among all three and hence methoxide anion is the strongest base.
Thus, the correct answer is - sodium acetate is the least basic while sodium methoxide is the most basic.
When NH3(g) reacts with O2(g) to form N2O(g) and H2O(l), 342 kJ of energy are evolved for each mole of NH3(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation.
Answer: [tex]2NH_3(g)+2O_2(g)\rightarrow N_2O(g)+3H_2O(l)+684kJ[/tex]
Explanation:
The skeletal thermochemical equation for the reaction is:
[tex]NH_3(g)+O_2(g)\rightarrow N_2O(g)+H_2O(l)+342kJ[/tex]
The balanced thermochemical equation for the reaction is:
[tex]2NH_3(g)+2O_2(g)\rightarrow N_2O(g)+3H_2O(l)+684kJ[/tex]
When 1 mole of [tex]NH_3[/tex] reacts with oxygen , heat released = 342 kJ
Thus when 2 moles of [tex]NH_3[/tex] reacts with oxygen , heat released = [tex]\frac{2}{1}\times 342 kJ=684kJ[/tex]
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
Which fossil fuel was formed from the bodies of prehistoric animals and plants?
Answer:
coal
Explanation:
Only 5 minutes to answer!
Why are the weather satellites important on Mars?
Answer:
they can track the weather which can show if it would be posssible to live or have life on mars
Explanation:
Suppose you have a 1:1:1 by weight mixture of three solid compounds, salicylic acid 4-nitroaniline naphthalene. You dissolve 1 gram of this mixture in diethyl ether, and place a tiny drop of the ether solution on a TLC plate. After developing the TLC plate, you see three spots. Which compound would would you expect to have the largest Rf value
Answer:
The correct answer is - 4-nitroaniline.
Explanation:
It is given that all three solid compounds salicylic acid + 4-nitroaniline + naphthalene are equal in the ratio in the mixture and then 1 gram of this mixture is dissolved in the diethyl ether and run a drop of the solution on TLC plate. This plate shows three spots.
The salicylic acid and naphthalene would stay dissolved in the diethyl ether solution due to the 4-nitroaniline could be extracted by adding aqueous acid and involve in the aqueous layer and thus spot of 4-nitroaniline would be with largest Rf value.
Which one is it for a brialiest
Help it’s about Binary compounds and transition metals
Answer:
Cr 6+ & SO4 2-
Explanation:
Sulfate is a polyatomic ion that has a charge of 2-. There are three of them in the chemical formula so it equates to a 6- total charge. Thus, chromium must have a 6+ charge to give the compound a neutral charge.
why do we need digital technology in school?
Answer: See explanation
Explanation:
Digital technologies refers to the electronic tools, or devices that can be used to generate data, store them or process data. e.g. mobile phones, ebooks etc.
Digital learning makes use of technology. Effective use of digital learning tools can help increase the engagement of students. This csn.aksi be used by the teachers to enhance personalized learning and also improve the lesson plans.
Digital technology can enhance collaboration, and communication with the students. The use of videos, robots, virtual classrooms, augmented reality and other technologies can bring about fun and foster inquisitiveness.
How many grams are in 3.0 moles of sodium chloride (NaCl)?
Answer:
175.5
Explanation:
Use the following Balanced Equation to complete the question: 2 Al + 6 HBr → 2 AlBr3 + 3 H2
If you have 10 moles of Al how many moles of H2 can be produced?
*Will give Brainly!*
Compare the number of moles calculated in parts a) 0.03 and b). 0.064. Which of the three possible reactions discussed is consistent with these results?
Answer:don’t click link ur gonna get ur info taken
Explanation:
Help me I'm desperate :( no links or u will be reported
Answer:
Here is the answer from somewhere in the internet
What is the ratio by atoms of elements present in technetium (VII) peroxide? (peroxide
is a polyatomic ion)
1:7
2:8
4:9
3:1
Answer: 1:7
Explanation: 2 Tc^+7 + 7 O2^-2 -> Tc2 (O2)7
Also 2 Tc to 14 O
Question 6 of 10
How much energy is required to vaporize 2 kg of gold? Use the table below
and this equation: Q = mLvapor
Substance
Latent Heat
Fusion
(melting)
(kJ/kg)
Melting
Point
(°C)
Latent Heat
Vaporization
(boiling) (kJ/kg)
Boiling
Point
(°C)
Aluminum
400
660
1100
2450
Copper
207
1083
4730
2566
Gold
628
1063
1720
2808
Helium
52
-270
21
-269
Lead
24.5
327
871
1751
Mercury
11.4
-39
296
357
Water
335
0
2256
100
Answer: Q = mlvap
Q = (2 kg)(1 kmol/197 kg)(1,000 mol/1 kmol)
Q = 10.15 kJ
2126 joules of energy in form of thermal energy is required to vaporize 2 kg of gold.
What is thermal energy?Thermal energy is defined as a type of energy which is contained within a system which is responsible for temperature rise.Heat is a type of thermal energy.It is concerned with the first law of thermodynamics.
Thermal energy arises from friction and drag.It includes the internal energy or enthalpy of a body of matter and radiation.It is related to internal energy and heat .It arises when a substance whose molecules or atoms are vibrating faster.
These vibrating molecules and atoms collide and as a result of which heat is generated in a substance , more the collision of particles , higher is the thermal energy.
Amount of heat is calculated as, Q=2×1063 =2126 joules as per the given formula.
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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.
Which element had the smallest atomic radius
Answer:
helium is the answer
Explanation:
helium is the smallest element in francium is the largest hope this helps
How many mL of 0.715 M HCl is required to neutralize 1.25 grams of sodium carbonate? (producing carbonic acid)
I really couldn't find the answer since molarity and volume for sodium carbonate are not given.
I will mark the correct answer with steps as best answer.
Answer:
34 mL
Explanation:
We'll begin by calculating the number of mole in 1.25 g of sodium carbonate, Na₂CO₃. This can be obtained as follow:
Mass of Na₂CO₃ = 1.25 g
Molar mass of Na₂CO₃ = (23×2) + 12 + (16×3)
= 46 + 12 + 48
= 106 g/mol
Mole of Na₂CO₃ =?
Mole = mass /molar mass
Mole of Na₂CO₃ = 1.25 / 106
Mole of Na₂CO₃ = 0.012 mole
Next, we shall determine the number of mole HCl needed to react with 0.012 mole of Na₂CO₃.
The equation for the reaction is given below:
Na₂CO₃ + 2HCl —> H₂CO₃ + 2NaCl
From the balanced equation above,
1 mole of Na₂CO₃ reacted with 2 moles of HCl.
Therefore, 0.012 mole of Na₂CO₃ will react with = 0.012 × 2 = 0.024 mole of HCl.
Next, we shall determine the volume of HCl required for the reaction. This is illustrated:
Mole of HCl = 0.024 mole
Molarity of HCl = 0.715 M
Volume of HCl =?
Molarity = mole /Volume
0.715 = 0.024 / volume of HCl
Cross multiply
0.715 × volume of HCl = 0.024
Divide both side by 0.715
Volume of HCl = 0.024 / 0.715
Volume of HCl = 0.034 L
Finally, we shall convert 0.034 L to mL
This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.034 L = 0.034 L × 1000 mL / 1 L
0.034 L = 34 mL
Therefore, 34 mL of HCl is needed for the reaction.
The amount of HCl required for counterbalancing 1.25 g of Na2CO3(Sodium Carbonate) would be:
- [tex]34 ml[/tex]
Given that,
Mass of Na2CO3 [tex]= 1.25 g[/tex]
To find the Moles of Na2CO3, we will find the molar mass of Na2CO3,
Molar Mass of or Na2CO3 [tex]= 106 g/mol[/tex]
So,
Moles of Na2CO3 [tex]= mass /molar mass[/tex]
[tex]= 1.25/106[/tex]
[tex]= 0.012 mol[/tex]
To determine the quantity of HCl required to display the reaction with 0.012 mol of Na2CO3
[tex]Na_{2} CO_{2} + 2HCl[/tex] → [tex]H_{2}CO_{3} + 2NaCl[/tex]
While balancing the equation, we know that [tex]0.012[/tex] × [tex]2 = 0.024 mole of HCl[/tex] is necessary to process the reaction.
Now,
As we know,
HCl moles [tex]= 0.024[/tex]
Molarity of HCl [tex]= 0.715 M[/tex]
∵ Quantity of HCl required = Moles/Molarity
[tex]= 0.024 / 0.715[/tex]
[tex]= 0.034 l[/tex] [tex]or 34ml[/tex]
Thus, 34 ml is the correct answer.
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A 72.0 g sample of an organic solid is dissolved in 180mL of water. The solid is extracted using one 60 mL extraction in the first extraction of an organic solvent which has a partition (distribution) coefficient with water of 10. The first extraction removed 55.4 g of solid from water. What are the numbers that need to go in box A and B to calculate the volume of solvent (y) that would be necessary to remove an additional 7.0g from the remaining sample dissolved in water. You DON'T have to complete the calculation to solve for y.
Answer:
[tex]V_{7.0}\approx 235ml[/tex]
Explanation:
From the question we are told that
mass of sample [tex]M=72.0 grams[/tex]
volume of water [tex]V=180 mL[/tex]
volume for extraction [tex]V'=60mL[/tex]
partition (distribution) coefficient water [tex]d=10[/tex]
initial extraction removal [tex]x=55.4g[/tex]
Generally the equation for the weight of sample [tex]x_n[/tex] is mathematically given by
[tex]x_n=x*(\frac{DV}{DV+V'})^n[/tex]
[tex]x_n=55.4(\frac{10*180}{10*180+60})^1[/tex]
[tex]x_n=53.613g[/tex]
Generally the weight extracted [tex]x_e[/tex] is therefore
[tex]w_e=x-x_n[/tex]
[tex]w_e=55.4-53613[/tex]
[tex]w_e=1.787[/tex]
[tex]w_e=1.787[/tex] is extracted with 60ml solvent .
Therefore volume of solvent (y) that would be necessary to remove an additional 7.0g
[tex]V_{7.0}=\frac{60}{1.767}*7[/tex]
[tex]V_{7.0}=235.030ml[/tex]
[tex]V_{7.0}\approx 235ml[/tex]
Which of the following methods of fossil formation is formed in dry areas due to a lack of moisture?
a
Mummification
b
Casts and molds
c
Amber fossil
d
Carbonization
The methods of fossil formation in dry areas due to a lack of moisture is mummification. The correct option is a.
What is mummification?Mummification is the process of deliberately drying or embalming flesh to preserve the body after death.
This typically entailed removing moisture from a deceased body and desiccating the flesh and organs with chemicals or natural preservatives such as resin.
Mummification served the purpose of keeping the body intact so that it could be transported to a spiritual afterlife.
The body was stripped, positioned on a slanted table, and washed in natron solution (a naturally occurring salt used both as soap and a preservative).
The brain was extracted from the skull through a hole in the ethmoid bone (the bone separating the nasal cavity from the skull cavity).
Thus, the correct option is A.
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A 1.om sample of dry air at
at 25°c at 786mmHg contains 0.925g Nitrogen Plus other gases including oxygen, argon and carbon dioxide. what is the partial pressure of Na with the air sample.
Answer:
Is the question not supposed to be what is the partial pressure of Nitrogen not Sodium
A balloon has a pressure of 3.5atm and a volume of 4.2L. What will the volume of the balloon be if the pressure is increased to 7.0atm? Assume that temperature remains constant. SHOW ALL WORK FOR FULL CREDIT!
The volume of the balloon is 2.1L.
What is volume?Volume is the amount of space the matter occupies. The SI unit of volume is cubic meter.
Using Boyles law equation,
P1V1 = P2V2
Where P1 and V1 are the initial pressure and volume of the gas
P2 and V2 are the final pressure and volume of the gas
Given:
P1 = 3.5atm
V1 = 4.2L
P2 = 7.0atm
V2 = ?
Solve for V2 ,
V2 = P1V1/P2
V2 = (3.5atm x 4.2 L) / (7.0atm)
= 2.1L
Hence, the volume of the balloon is 2.1L.
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