Answer:
4.255 J/ K
Explanation:
Given data :
mass of Gallium = 16 gm
molar mass = 69.723 g/mol
hence no of moles = 16 / 69.723 = 0.23 moles --------- ( 1 )
Δh ( heat fusion ) = 5.59 KJ/mol
Temperature = 29.8°C = 302.8 k
Determine the entropy change of gallium
Δs ( entropy change ) = heat fusion / temperature
= ( 5.59 * 1000) J/mol / 302.8 = 18.46 J/k*mol
Hence entropy change of gallium
= Δs * no of Gallium moles
= 18.46 * 0.23 = 4.255 J/ K
Which statement best illustrates how mixtures and pure substances are different?
Mixtures have color; pure substances are colorless.
Mixtures have various odors; pure substances are odorless.
Mixtures are found on the periodic table; pure substances are not.
Mixtures are physically combined; pure substances are chemically combined.
Answer:
Mixtures are physically combined and pure substances are chemically combined.A student was directed to convert the mass of a boulder from kg to pounds.
Conversion factor: 1 pound = 454 g
The mass is 22 kg. The student calculated the weight to be 0.048 pounds.
Is this correct? If not, what went wrong?
Answer:
Incorrect
Explanation:
Given that,
The mass of a boulder, m = 22 kg
We need to find the weight of the student in pounds.
We know that,
1 pound = 454 g
or
1 g = (1/454 pounds)
22 kg = 0.022 grams
So,
0.022 grams = [tex]\dfrac{0.022}{454}\ pounds[/tex]
= 0.000048 pounds
The student says the weight is 0.048 pounds. It means he was incorrect.
anyone know the name of this structure please
Any help?
The Kb for hydroxylamine, HONH2, is 1.1 x 10 -8
. What would be the pH of a solution
prepared by placing 1.34 g of HONH2 in 0.500 L of water?
Answer:
pH = 9.475
Explanation:
Hello there!
In this case, according to the basic ionization of the hydroxylamine:
[tex]HONH_2+H_2O\rightarrow HONH_3^++OH^-[/tex]
The resulting equilibrium expression would be:
[tex]Kb=\frac{[HONH_3^+][OH^-]}{[HONH_2]} =1.1x10^{-8}[/tex]
Thus, we first need to compute the initial concentration of this base by considering its molar mass (33.03 g/mol):
[tex][HONH_2]_0=\frac{1.34g/(33.03g/mol)}{0.500L} =0.0811M[/tex]
Now, we introduce [tex]x[/tex] as the reaction extent which provides the concentration of the hydroxyl ions to subsequently compute the pOH:
[tex]1.1x10^{-8}=\frac{x^2}{0.0811-x}[/tex]
However, since Kb<<<<1, it is possible to solve for [tex]x[/tex] by easily neglecting it on the bottom to obtain:
[tex]x=[OH^-]=\sqrt{1.1x10^{-8}*0.0811}= 2.99x10^{-5}[/tex]
Thus, the pOH is:
[tex]pOH=-log(2.99x10^{-5})=4.525[/tex]
And the pH:
[tex]pH=14-4.525\\\\pH=9.475[/tex]
Regards!
How are ocean waves formed? gravity energy transfer conduction radiation
Answer:
I apologize that I'm late and all But your answer is B. Energy Transfer.
Explanation:
The waves transfer energy to the sand for example.
Using the following equation:
2 NaOH + H2SO4 à 2 H2O + Na2SO4
How many grams of sodium sulfate will be formed if you start with 200 grams of sodium hydroxide and you have an excess of sulfuric acid?
5 points! Please don’t guess if u don’t know!
Salts usually have a low melting point.
A. true
B. false
This is true. that's why we use it for snow
Answer:
false
Explanation:
ya thats why we use it for boiling water
What is the difference between global warming and climate change? *
1 point
There is no difference, we can use either term
Climate change happens because of humans, global warming happens naturally
Global warming focuses only on temperature increases, climate change only focuses on temperature decreases
Global warming focuses only on temperature increasing, climate changes is a broader term that refers to the range of changes happening on Earth in addition to temperature changes
Answer: D: Global warming focuses only on temperature increasing, climate changes is a broader term that refers to the range of changes happening on Earth in addition to temperature changes
Explanation:
Answer:
what he/she said
Explanation:
describe one similarity and one difference between amylopectin and glycogen?
Answer: The main difference between amylopectin and glycogen is that amylopectin is an insoluble form whereas glycogen is a soluble form. The 1,4-alpha glycosidic bonds form the linear chain of both amylopectin and glycogen while 1,6-alpha glycosidic bonds form the branches.
Explanation:
Concentration is ? 
what is the name of this structure here please and thanks
Answer:
look at the file that the other person sent
HELP!
The law of conservation of energy states:
A. Energy increases exponentially with times
B. Total energy decreases due to energy output.
C. Energy cannot be created or destroyed.
D. Energy always remains in the same form.
Answer:
C
Explanation:
energy cannot be created or destroyed like solar energy for instance. it is already energy because it comes from the sun and for other reason.
Hope this helps!
help out here plzzzzzzzzzzzzz
Answer:
Chromosomes are duplicated in the "s phase" of interphase.
Whats molecular formula of 26,4% carbon , 3,3 % Hydrogen and 70,3% oxygen?
Explanation: Therefore the molecular formula is twice the empirical formula: C2H6O2. The compound dioxane contains only carbon, hydrogen, and oxygen. When 0.956 g dioxane is burned, 1.91 g carbon dioxide and 0.782 g water are formed. In another experiment, it was determined that 6.04x10-3 mol dioxane weighs 0.532 g.
igneous sedimentary, and metamorphic rocks are found at the same cliff side.Which statement is correct?
Answer:
The metamorphic rock and sedimentary rock were already at this location and magma flowed into other rocks
Explanation:
Which group of reptiles is the largest in terms of body size?
Answer : if you have time for learning and is in 6th grade the anwser is crocodilians
Explanation: i got it right
Why glucose (monosaccharide) and maltose (disaccharide) give positive Benedict test?
Answer:
please give me brainlist and follow
Explanation:
Substance in water + 3 mL Benedict's solution, then boil for few minutes and allow to cool. The common disaccharides lactose and maltose are directly detected by Benedict's reagent because each contains a glucose with a free reducing aldehyde moiety after isomerization.
Glucose and maltose give a positive Benedict test because they have a free carbonyl group to undergo oxidation.
Explanation:
The monosaccharides are sugars that cannot be further hydrolyzed into simpler sugars like glucose, fructose, ma, etc.The disaccharides are sugars that on hydrolysis give two monosaccharide units like sucrose, lactose, maltose, etc.The polysaccharides are sugars that on hydrolysis give more than two monosaccharide units like sucrose, lactose, maltose, etc.Reducing sugars are which have a free carbonyl group that oxidizes into a carboxylic acid and reduces Benedict reagent like glucose, maltose, etc.Non-reducing sugars which don't have a free carbonyl group like sucrose, all polysaccharides, etc.Benedict test is a chemical test performed to test the presence of reducing sugars.The Benedict reagent is a complex made up of sodium citrate, sodium carbonate, and copper sulfate pentahydrate.The positive test for reducing sugar will be the red coloration of the solution due to the formation of copper(II) oxide.So, from this, we can conclude that glucose and maltose give a positive Benedict test because they have a free carbonyl group to undergo oxidation.
Learn more about carbohydrates:
brainly.com/question/3950786?referrer=searchResults
brainly.com/question/1157431?referrer=searchResults
How much mass of water (H₂O) do I need to mass out if I need 2.5 moles for a reaction?
Answer:
45g
Explanation:
Use the Mole = Mass x Mr equation:
Rearrange the above equation to find mass,
Mass = 2.5 moles x 18 (Mr of H₂O) = 45g
Therefore answer is 45g
Answer:
Given
number of moles (n) =2 . 5 mol
R.tc maas of H2O (m) =?
sln
H2O =(1x2+16)
=18g/mol
n=m/mr
m=nxmr
m=2.5x18
m=45g
mass of water is 45g
Ammonium phosphate is an important ingredient in many solid fertilizers. It can be made by reacting aqueous phosphoric acid with liquid ammonia. Calculate the moles of ammonium phosphate produced by the reaction of of ammonia. Be sure your answer has a unit symbol, if necessary, and round it to significant digits.
The given question is incomplete. The complete question is:
Ammonium phosphate [tex](NH_4)_3PO_4[/tex] is an important ingredient in many solid fertilizers. It can be made by reacting aqueous phosphoric acid [tex]H_3PO_4[/tex] with liquid ammonia. Calculate the moles of ammonium phosphate produced by the reaction of 1.7 mol of ammonia. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer: 0.57 moles of ammonium phosphate are produced by the reaction of 1.7 moles of liquid ammonia
Explanation:
The balanced chemical equation is:
[tex]H_3PO_4+3NH_4OH\rightarrow (NH_4)_3PO_4+3H_2O[/tex]
According to stoichiometry:
3 moles of liquid ammonia [tex](NH_4OH)[/tex] produces = 1 mole of ammonium phosphate [tex](NH_4)_3PO_4[/tex]
Thus 1.7 moles of liquid ammonia [tex](NH_4OH)[/tex] produces = [tex]\frac{1}{3}\times 1.7=0.57[/tex] mole of ammonium phosphate [tex](NH_4)_3PO_4[/tex]
Thus 0.57 moles of ammonium phosphate are produced by the reaction of 1.7 moles of liquid ammonia
What is the name of PbS2
Answer:
Lead sulfide.
Explanation:
The distance that is covered by the wave in one second is called
Answer:
The distance that is covered by the wave in one second is called frequency.
Explanation:
The following pairs of soluble solutions can be mixed. In some cases, this leads to the formation of an insoluble precipitate. Decide, in each case, whether or not an insoluble precipitate is formed.
a. AlCl3 and K3PO4
b. RbCO3 and NaCl
c. Na2CO3 and MnCl2
d. K2S and NH4Cl
e. CaCl2 and (NH4)2CO3
Answer:
See explanation
Explanation:
Let us see what happens when each solution is mixed;
a) AlCl3(aq) + K3PO4(aq) ------> 3KCl(aq) + AlPO4(s)
A precipitate is formed here
b) RbCO3(aq) + NaCl(aq) -------> This is an impossible reaction hence no solid precipitate is formed here
c) MnCl2(aq) + Na2CO3(aq) → 2NaCl(aq) + MnCO3(s)
A precipitate is formed.
d) K2S(aq) + 2NH4Cl(aq) ------> 2KCl(aq) + (NH4)2S(aq)
No solid precipitate is formed
e) CaCl2(aq) + (NH4)2CO3(aq) → CaCO3(s) + 2NH4Cl(aq)
A solid precipitate is formed
how many core electrons does magnesium ion have
Answer:
10 core electrons
Explanation:
Answer:
Magnesium has 10 core electrons
Predict the shape of the molecule.....
Answer:
bent
Explanation:
What are the chemical symbols for the elements calcium, carbon, and chlorine respectively? es
A) CL, C, and Ce
B) C, Ca, and Co
C) Ca. C, and CL
D) Ca, Co, and CL
Answer:
C
Explanation:
How much NaCl would you dissolve and dilute to the 100.00 mL mark in a volumetric flask with DI H2O to prepare a 0.825 M sodium chloride solution?
Answer:
4.82 g
Explanation:
To solve this problem we'll use the definition of molarity:
Molarity = moles / litersWe are given the volume and concentration (keep in mind that 100mL=0.100L):
0.825 M = moles / 0.100 LNow we calculate the number of NaCl moles required:
moles = 0.0825 molThen we convert 0.0825 NaCl moles into grams, using its molar mass:
0.0825 mol * 58.44 g/mol = 4.82 gChlorination of phenol gives para product but bromination of phenol gives Ortho para product why
Answer:
here you go
Explanation:
The reaction of phenol with bromine is known as bromination of phenol. Solvent has great influence on the reaction. In different solvents, different products are obtained. The action of bromine on phenol can be explained as:
Reaction with bromine in water:—-
Reaction with bromine in water
Phenol reacts with bromine water to give 2,4,6-tribromophenol.
In water, ionisation is facilitated. Phenol gets ionised to form phenoxide ion, which is even better ortho,para-directing. Bromine also gets ionised to a larger extent to form a large number of bromonium ions. And Bromine ions are highly stabilized in ionic solvents. So the formation of strong o,p-directing group and stabilization of Br+ enhances the formation of tribromophenol.
Reaction with bromine in CS2:—-
Reaction with bromine in non-polar organic solvents
Phenol reacts with bromine in a presence of Carbon disulphide to form a mixture of o-bromophenol and p-bromophenol. Among which p-bromophenol predominates. In CS2 ionisation is not facilitated that much. As it is a non-polar solvent it doesn't the Br+ on. Also −OH group is moderately o,p-directing. So as usual para-product is more formed.
A balloon filled with helium has a volume of 30.0 L at a pressure of 100 kPa and a temperature of 15.0°C. What will the volume of the balloon be if the temperature is decreased to -80.0°C and the pressure remains constant?
Answer:
[tex]V_2=20.1L[/tex]
Explanation:
Hello there!
In this case, since this is a problem in which the pressure of the gas remains constant, we can use the Charles' law as a directly proportional relationship between temperature (in Kelvins) and volume given by:
[tex]\frac{V_2}{T_2} =\frac{V_1}{T_1}[/tex]
Thus, solving for the final volume as the temperature is decreased to -80.00 °C, we obtain:
[tex]V_2=\frac{V_1T_2}{T_1}[/tex]
[tex]V_2=\frac{30.0L*(-80+273)K}{(15+273)K} \\\\V_2=20.1L[/tex]
Best regards!
What might happen if an endocrine hormone such as thyroid hormone was controlled by positive instead of negative feedback?
Answer:
cdg I will be a little late to the party but I have to go to the store and get ❤️❤️❤️❤️❤️❤️
150. g of aluminum chloride in 0.450 liters of solution, what is the concentration? (any examples are helpful, thank you)
Answer:
2.49 M
Explanation:
Step 1: Given data
Mass of AlCl₃: 150. gVolume of solution: 0.450 LStep 2: Calculate the moles AlCl₃ (solute)
The molar mass of AlCl₃ is 133.34 g/mol.
150. g × 1 mol/133.34 g = 1.12 mol
Step 3: Calculate the molar concentration of AlCl₃
Molarity is equal to the moles of solute divided by the liters of solution.
M = 1.12 mol/0.450 L = 2.49 M