Answer:
"Endothermic reaction: In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings of the reaction."
Explanation:
When enthalpy is positive and delta H is greater than zero, this means that a system absorbed heat. This is called an endothermic reaction. When enthalpy is negative and delta H is less than zero, this means that a system released heat. This is called an exothermic reaction.
What does a high positive enthalpy mean?
The sign of q for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is exothermic if heat is released by the system into the surroundings. Because the surroundings are gaining heat from the system, the temperature of the surroundings increases.
Learn more about the endothermic reaction here: brainly.com/question/6506846
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I need help with question 5
Answer:
B a spring being stretched
Plants in forests take up carbon dioxide from the atmosphere during photosynthesis. They transform the carbon dioxide into plant material. When plants die, their organic matter is often worked into the soil by decomposers. Some of this organic matter remains within the soil and forest floor, and some of it is taken up by other living things.
Based on this information, what role do forests play in the carbon cycle?
A.
Forests are carbon sinks because they store carbon.
B.
Forests are carbon sinks because they do not absorb carbon dioxide when plants die.
C.
Forests are carbon sources because they emit carbon.
D.
Forests are carbon sources because they can be burned to emit carbon dioxide.
Answer: B. forests are carbon sinks because they store carbon
Explanation:forests take up carbon from the atmosphere through photosynthesis and from organic matter through decomposition. so, forests are carbon sinks because they store carbon
How many moles of KOH are there in 27.5 mL of 0.250 M KOH?
Question 2 options:
4.31 × 10−3 mol KOH
6.88 × 10−3 mol KOH
7.24 × 10−3 mol KOH
8.13 × 10−3 mol KOH
9.21 × 10−3 mol KOH
Answer:
6.88 × 10^-3mol
Explanation:
Molarity = number of moles (n) ÷ volume (V)
According to this question, there in 27.5 mL of 0.250 M KOH, the number of moles of KOH can, therefore, be calculated as follows:
number of moles = molarity × volume
Volume of KOH = 27.5mL = 27.5/1000
= 0.0275L
n = 0.0275 × 0.250
n = 0.006875 mol
n = 6.88 × 10^-3mol
Please help me
will give the brainliest!
Explanation:
a) The presence of sulfate ions in a solution can be confirmed by the reaction of barium chloride in an acidic medium.
The balanced chemical equation of the reaction is shown below:
[tex]BaCl_2(aq)+CuSO_4(aq)->CuCl_2(aq)+BaSO_4(s)[/tex]
Hence, the white precipitate is barium sulfate and its formation with the ionic equation is shown below:
[tex]Ba^2^+(aq)+SO_4^2^-(aq)->BaSO_4(aq)[/tex]
b) The presence of copper (II) ions can be confirmed by the following test:
Add potassium iodide solution to copper (II) solution.
Then a white ppt of cuprous iodide along with the liberation of iodine is observed and the entire solution attains brown color.
The chemical equation of the reaction is shown below:
[tex]2CuSO_4(aq)+4KI(aq)->Cu_2I_2(s)+I_2(s)+2K_2SO_4(aq)\\[/tex]
c)(i)Due to this reaction, the blue color of the solution becomes white.
Reddish-brown copper is deposited at the bottom of the container.
(ii)In this reaction, zinc is oxidized.
d) (i) Copper is produced at the cathode.
(ii)[tex]Cu^2^+(aq)+2e^-->Cu(s)[/tex]
(iii) The reaction that takes place at the cathode is reduction.
Reduction is gaining of electrons.
A pupil has drawn the electronic structure of fluorine and the diagram is shown below. However,
mistakes have been made. State three mistakes that have been made.
Fl atomic number: 9
Fl atomic mass: 10
(ps i have two of these but can’t figure out the last)
Answer:
The number of electrons in the orbit is wrong they have to be 9 and not 10since flourine is in group 7 the number of electrons in the outer most shell has to be 7 and not 2the first shell has 8 instead of 2 electronsI hope this helps
HELLO EVERYONE PLEASE I NEED HELP WITH
Please I REALLY NEED A HELP WITH THIS PLEASE HELP ME
THIS HARRY POTTER LITERARY ESSAY
OUTLINE
1. Love and Friendship is a central theme in Harry Potter and the Philosopher's Stone. Prove that this statement is true using 2(two) different characters from the novel as examples.
Introductory Statement/ Hook:
Statement of Intent: reason A and B :
thesis reason A and B:
BODY PARAGRAPH
#1 Point #1: Introduce REASON A here, but use general statement
#1: Provide quotations from the novel to support Reason A
Explanation #1:
Proof #2:
Explanation #2:
BODY PARAGRAPH
#2 Point #2: Introduce REASON B here, but use general statements
#1: Provide quotations from the novel to support ReasonB
Explanation #1:
Proof #2:
Explanation #2:
CONCLUSION
Restate/ Summarize Thesis:
Restate/ Summarize Points:
Answer:
Ron and Hermoine
Explanation:
They always fought over petty things, but at the end, they did end up together!
(Answer for your question about love and friendship being a central theme in Harry Potter and the Philosopher's stone)
*ALSO, MY ANSWER MIGHT BE WRONG* so be sure to use a pencil just in case!
QUICK CHECK
Use the periodic table to select which type of bond is present and which of the listed properties is most
likely for each substance.
Substance
Type of bond
Likely property
A А
B
A
Cuzm
Ba
lonic
DO
covalent
02
С
D
metallic
Answer:
Coppell zinc,ironic bond
Explanation:
lt will give away two zinc atoms
Answer:
I will go with Sodium chlorine NaCl
Which is another word for 10 meters in the metric system?
Answer:
Dekameter
Explanation:
Draw the following structures and name them :
I. CH3CH2(OH)
II.CH3CH2CH(CH3)C(Cl)2C(l)2CH(F)OH
III.CH3CH(CH3)CHO
IV.CH2=CH(OH)
V.CH3OCH2CH3
Answer:
hope this helps.answer is in the picture
Is this population more likely to grows slowly or quickly in the next 10 years
nobody can say it is uncertain but in my opinion it will grow quickly in the next 10 years
Name each compound. Do not capitalize element names. An example can be seen
below.
Ex. SF6: sulfur hexfluoride
a. H2O:
b. PC15:
C. SiF4:
d. N20
Answer:
a. H2O: dihydrogen monoxide
b. PCl5: Phosphorus pentachloride
c. SiF4: Silicon tetrafluoride
d. N20: dinitrogen oxide
How are the vapor pressure and boiling point of alkynes affected as the chain length increases?
Answer:
Answer to the following question is as follows;
Explanation:
Alkynes' vapour pressure and normal boiling points are altered when chain length grows, since vapour pressure rises while boiling point falls.
Vapour pressure always include pressure entered by vapour with its condensed phase, pressure include molecules force of attraction include vapour
Which element has 2 valence electrons in the 2s sublevel?
Answer:
beryllium is the answer.
I hope this will help you
Is FeS iron (ll) sulfide or iron (lll) sulfide?
Answer:
the valence of S is -2. For FeS to be neutral the valence of Fe used must be +2
and since Iron (II) has its valency 2, FeS will be Iron (II) Sulfide.
how much energy is required to melt 2kg of aluminium
option with explaination
Answer:
B. it's water of crystallization.
the water of crystallization, that is the number of molecules of water attached to One Copper atom gives blue color to the hydrated salt (CuSO4.5H2O)
An organic compound has the empirical formula C2H4O. what is the compound?
a. butanoic acid
b. butanol
c. ethanoic acid
d. ethanol
Answer:
The correct answer is - butanoic acid
Explanation:
An empirical formula is the general formula or base formula that is the simplest positive integer ratio of atoms present in a compound. The empirical formula is specific to specific compounds or types of compounds.
Among the given options, the empirical formula C2H4O is butanoic acid as the molecular formula of butanoic acid is - C4H8O2 which is multiple of C2H4O. Other compounds have different than this empirical formula.
True or false, The universal gas constant, R, is . 0821 when we use mm Hg as our unit for pressure
Answer:
False
Explanation:
R = gas constant = 0.0821 atm•L/mol•K
Hiii pls help me to write out the ionic equation
Answer:
STEP I
This is the balanced equation for the given reaction:-
[tex] 2KOH_{(aq)} + H_2SO_4{}_{(aq)} \rightarrow K_2SO_4{}_{(aq)} + 2H_2O_{(l)} [/tex]
STEP II
The compounds marked with (aq) are soluble ionic compounds. They must be
broken into their respective ions.
see, in the equation KOH, H2SO4, and K2SO4 are marked with (aq).
On breaking them into their respective ions :-
2KOH -> 2K+ + 2OH-H2SO4 -> 2H+ + (SO4)2-K2SO4 -> 2K+ + (SO4)2-STEP III
Rewriting these in the form of equation
[tex] \underline{\pmb{2K^+} }+ 2OH^- + 2H^+ + \pmb{\underline{{SO_4{}^{2-}}} \: \rightarrow \: \underline{\pmb{2K^+}}} + \underline{\pmb{SO_4{}^{2-}}} + 2H_2O [/tex]
STEP IV
Canceling spectator ions, the ions that appear the same on either side of the equation
(note: in the above step the ions in bold have gotten canceled.)
[tex] \boxed{ \mathfrak{ \red{ 2OH^-{}_{(aq)} + 2H^+{(aq.)} \rightarrow H_2O{}_{(l)}}}} [/tex]
This is the net ionic equation.
____________________________
[tex] \\ [/tex]
[tex]\mathfrak{\underline{\green{ Why\: KOH \:has\: been\: taken\: as\: aqueous ?}}} [/tex]
KOH has been taken as aqueous because the question informs us that we have a solution of KOH. by solution it means that KOH has been dissolved in water before use.[Alkali metal hydroxides are the only halides soluble in water ]
Calculate the volume (in L) that 3.25 mol of helium gas will occupy at a temperature of 25.0 °C and a pressure of 799 mm Hg.
Answer:
V = 6.34 L
Explanation:
Given that,
Number of moles of Helium gas, n = 3.25 mol
Temperature, T = 25 °C = 298 K
Pressure, P = 799 mm Hg
We know that,
PV = nRT
Where
R is the gas constant, R = 62.4 L-mm Hg/mol K
So,
[tex]V=\dfrac{nRT}{P}\\\\V=\dfrac{3.25\times 62.4\times 25}{799}\\\\V=6.34\ L[/tex]
So, the volume of the gas is 6.34 L.
. The Ksp of barium sulfate is 1.1 × 10–10. What is the sulfate-ion concentration of a 1.0-L saturated solution of BaSO4 to which 0.025 mol of Ba(NO3)2 is added? 4.4 × 10–9M 1.0 × 10–5M 6.6 × 10–5M 2.8 × 10–12M
Answer:
[tex][SO_4^{2-}]=4.4*10^{-9}M[/tex]
Explanation:
From the question we are told that:
[tex]Ksp=1.1*10^{-10}[/tex]
Volume of [tex]SO_4^{2-}=1.O[/tex]
Moles of [tex]Ba(NO_3)^2 =0.025[/tex]
Generally the equation for Ksp is mathematically given by
[tex]Ksp=[Ba^{2+}][SO_4^{2-}][/tex]
[tex]1.1*10^{-10}=[0.025][SO_4^{2-}][/tex]
Therefore
[tex][SO_4^{2-}]=4.4*10^{-9}M[/tex]
HELP ME PLZ Which of the following describes the structure of a fish's swim bladder?
A. Expands and contracts to allow the fish to rise or sink in the water
B. Internal organ filled with liquid
c. Holds urine until it can be released into the environment
D. Internal organ filled with air sacs
What is the name of the molecule shown below?
A) ethanol
B) ethanal
C) ethanoic acid
D) ethylamine
The name of the molecule shown is Ethanol.
What is Ethanol?Ethanol is a alcoholic substance that is formed from fermentation of glucose in the presence of yeast or microorganisms.
It has a chemical group that have methyl group, hydroxyl group OH which is bonded to carbon atom.
Therefore, The name of the molecule shown is Ethanol.
Learn more about ethanol below.
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plz answer (g) i will give rating 5 and thanks who answer plz fast
Answer:
Like many common group 2 metal carbonates, magnesium carbonate reacts with aqueous acids to release carbon dioxide and water
MgCO3 + 2 HCl → MgCl2 + CO2 + H2O.
The procedure to obtain pure magnesium chloride from the reaction is as thus
Step 1: Reaction
- Leave the dilute hydrochloric acid in a beaker.
- Add Magnesium carbonate slowly until it is in excess or until no more gas seem to be getting liberated.
Step 2: Filtration
- Filter with filter paper and funnel.
- Filter off the excess magnesium carbonate as magnesium chloride will be in aqueous form (liquid) and will come out with the filtrate. The residue is the excess magnesium carbonate.
Step 3: Crystallization to obtain solid crystals from the filtrate.
- Pour filtrate solution into evaporating dish/basin
- Provide heat using Bunsen burner
- Pour solution into an evaporating basin and heat over a water bath
- Stop heating when crystals start to form
allow water to evaporate until pure crystals remain.
- Dry crystals using absorbent paper or warm oven.
Precautions
- Use personal protective equipment such as gloves, a lab coat and wear eye protection, especially when heating.
- Avoid inhaling unnecessary gases during the whole process.
what is the molarity of HCL solution that has a density of 1.17g/ml at 25°?
Here, we have been given that;
$ \bf{1 ml}$ = 1.17 g$ \bf{1 l}$ = 1170 gHence, we can note that,
No. of moles of HCL (n) = $ \sf{\frac{1170}{36.5}}$(n) = 32.05
[tex] \\ [/tex]
Thus,
Molarity = 32.05 mg/LHence, molarity of the given solution will be 32.05 mg/L.
Over a period of 2 minutes, 180 coulombs of charge pass through a resistor. What is the current through the resistor during this time?
Type the correct answer in the box. Use numerals instead of words.
The current through the resistor during this time is
A.
Answer:
Explanation:
Formula
The current = charge / time
The charge is in coulombs
The time has to be in seconds.
1 minute = 60 seconds
2 minutes = 120 seconds.
charge = 180 coulombs
current = 180 / 120
current = 1.5 amperes.
What is the percent yield of a reaction?
O A. The difference between measured and calculated amounts
OB.
The amount of produd obtained
amount possible
* 100
C. The amount of product actually obtained in a reaction
D. The amount of product that is possible from a reaction
Answer:
B. The amount of produd obtained/amount possible * 100
Explanation:
In chemistry, the yield of a chemical reaction is the quantity or amount of products obtained in that chemical reaction. It is calculated by using the following formula:
Percentage yield = Actual yield/theoretical yield × 100
- The actual yield is the amount of products got from a chemical reaction
- The theoretical yield is the amount of product got from using the balanced equation (stoichiometry).
CORRECT ANSWER ONLY ND WILL GIVE BRAINLIEST✌
Calculate the mass of nitrogen dioxide gas that would occupy
the same volume as 10g of hydrogen gas at ē same pressure and temperature
(H= 1.0 N = 14.0 O= 16.0) GAS LAWS/MOLES
Answer:
150g
Explanation:
Assuming they are ideal gases at the same temperature and pressure, equal moles of gasses have equal volume. IN this case, if we have 10g of hydrogen gas, that is 5 moles of H2 gas. That means 5 moles og NO2 will occupy the same volume which is 5*(14.0 + 16.0*2) = 230 g
What happens if kinetic energy of a gas is lowered
Answer:
"If you lower the kinetic energy of a gas its temperature will decrease because temperature is a measure of the average kinetic energy of a substance."
Explanation:
Which pair of substances would react the
fastest?
a. Copper sheet and concentrated
nitric acid.
b. Copper powder and dilute nitric acid
C. Copper powder and concentrated
nitric acid.
Answer:
C. It has the highest rate of reaction. Copper has the highest TSA/V and concentrated nitric acid has huggest num of solute
