Answer:
resend again that question dear
write an importance of endothermic reactions
Answer:
the uses of exothermic reactions are:
1) lighting of stove
2) self heating cans
3) hand warmers
4) in some case exothermic process can be used to cook food such as rice (by adding calcium oxide to water heat is evolved and it helps to cook food )
Explanation:
hope this helps you pls mark me as brainilst
How many g of water are required to be mixed with 11.75 g of HgCl in order to make a 0.01 m solution? (Refer to the periodic table for atomic weights.)
a.) 40 g
b.) 5,000 g
c.) 2 x 10^8 g
d.) 2 x 10^6 g
The general name for a substance added to a reaction that affects the rate but is not consumed in the reaction is called a_____.
a.)constituent
b.)catalyst
c.)complex
d.)reactant
The action of a catalyst can be explained in the following manner:
a.) The catalyst makes it possible for the reaction to take place by another path that makes possible reaction at a lower energy.
b.) The catalyst takes no part in the reaction but serves as a buffer between reactants and products.
c.) The catalyst prevents the reverse reaction.
d.) The catalyst lowers the temperature of the reactants.
The energy level necessary to enable a reaction to occur is called the_____ energy.
a.) potential
b.) kinetic
c.) activation
d.) nuclear
Raising the temperature of a reacting system increases the rate of the reaction, but does NOT increase the:
a.) number of collisions
b.) average velocity of the reacting particles
c.) activation energy
d.) vibrational motions within the molecules
e.) fraction of the reacting particles which possess energies greater than the activation energy
Answer:
5,000 g
b.)catalyst
The catalyst makes it possible for the reaction to take place by another path that makes possible reaction at a lower energy.
activation
activation energy
Explanation:
Formulae for molality = number of moles of solute/mass of solvent in kilograms
Number of moles of solute= 11.75g/236 g/mol = 0.0498 moles
0.01 = 0.0498/x
x= 0.0498/0.01
x= 5 Kg or 5000 g
A catalyst refers to any substance that alters the rate of reaction but remains unaffected at the end of the reaction. The catalyst lowers the activation energy of a reaction.
For a chemical reaction to occur, the substances participating in that reaction must possess energy which is greater than the activation energy of the reaction. The activation energy is a sort of energy barrier between reactants and products which must be surmounted before a reaction can take place.
When the temperature of a reaction system is raised, the molecules move faster and the number of effective collisions in the system increases. However, raising the temperature does not raise the activation energy of the system.
Formal charge is calculated by assigning each atom _____ the bonding electrons that it shares. Oxidation number is determined by assigning all the shared electrons of a particular bond to the atom with the _____ electronegativity. Multiple choice question. half; higher half; lower all; lower all; higher
Answer:
A). half, higher
Explanation:
The Formal charge is elaborated as the 'allocated charge to a molecules' atom' on the basis of the assumption that the electrons present in the chemical bond are equally split among the atoms. It is estimated by 'halving the no. of bonding electrons that encircle the atom.
While Oxidation number is characterized as the 'hypothetical charge of an atom that is present within a molecule.' It is also defined as 'the actual number of lost or gained electrons or the rate at which the electrons are gained or lost by an atom to develop a chemical bond along with the other atom.' It is calculated by allocating or sharing the electrons having the higher electronegativity belonging to a specific bond with the other. Thus, option A is the correct answer.
Convert 48,987 minutes to years
using the method of dimensional analysis
Answer:
Explanation:
48000 minutes [ 1 hour / 60 min ] 1 day / 24 hours ] [365 days / year]
48000 * [ 1/(60 * 24 * 365)]
48000 * [1 / 525600]
There are 0.0930954years in 48000 minutes
Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes leading to irreversible inactivity of these enzymes. If the amount of mercury in a polluted lake is 0.4 Hg/mL, what is the total mass in kilograms of mercury in the lake
Answer:
The total mass of mercury in the lake is 631,542.7 kg
Explanation:
Question: The given dimensions of the lake as obtained from a similar question posted online are;
The surface area of the lake, A = 100 mi²
The lake's average depth, d = 20 ft.
The concentration of the mercury, C = 0.4 μg Hg/mL = 0.4 × 10⁻⁶ kg Hg/L
Therefore, we have;
The volume of water mixture in the lake, V = A × d
∴ V = 100 mi² × 20 ft. = 2,787,840,000 ft.² × 20 ft. = 55,756,800,000 ft.³
1 ft³ = 28.31685 L
∴ 55,756,800,000 ft.³ = 55,756,800,000 ft.³ × 28.31685 L/ft.³ = 1.57885675 × 10¹² L
The total mass of mercury in the lake, m = C × V
∴ m = 0.4 × 10⁻⁶ kg Hg/L × 1.57885675 × 10¹² L = 631,542.7 kg
The total mass of mercury in the lake, m = 631,542.7 kg.
Which equation describes a physical change? i. H2O(s) ⟶ H2O(l) ii. Na+(aq)+Cl−(aq) +Ag+(aq)+NO3−(aq) ⟶ AgCl(s)+Na+(aq)+NO3−(aq) iii. CH3OH(g)+O2(g) ⟶ CO2(g)+H2O(g) iv. 2H2O(l) ⟶ 2H2(g)+O2(g) v. H+(aq)+OH−(aq)⟶ H2O(l)
Answer:
The answer is "Option i"
Explanation:
In this question, only option (i) is correct, and others were wrong which can be defined as follows:
In option (ii):
[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]
It is the complete ionic equation.
In option (iii):
[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]
It is the combustion reaction but a not balanced equation.
In option (iv):
[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]
It is the decomposition equation.
In option (v):
[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]
It is the complete ionic equation.
For each pair (4), choose the stronger bond:
1. H–F (single bond) or H–Cl (single bond)
2. C–C (single bond) or C=C (double bond)
3. F–F (single bond) or H–F (single bond)
4. O=O (double bond) or C=C (double bond)
Answer:
line 3
Explanation:
let me know if you have any questions
please answer correctly.
Answer: i dont know but yu got it
Explanation:
Plsss help with this ASAP TT
Answer: lithium- 3 protons, 3 electrons, 3 neutrons
Oxygen- nucleon no. 16, Atomic no. 8, 8 protons, overall charge (-2)
Sorry I don't the others. Hope this helps
Is water the only liquid? If not, name 5 more
Answer:
Is water the only liquid? If not, name 5 more
Water, ethanol, household bleach, blood, paint, milk, gasoline, mineral oil, acetone and butyl alcohol are examples of liquids. Liquids' properties allow them to flow or be poured easily into containers, lava
water is not the only liquid.
Answer:
apple juice, milk, smoothie, blood, urine
PLZ HELP ME
Which of these is an example of an example factor which affects the earths climate?
A - Decrease in the suns energy.
B - Warm and cold ocean currents.
C - Increase in atmospheric dioxide.
D - Release of dust during volcanic eruption
Answer:
D- Release of dust during volcanic eruption
Explanation:
During major explosive eruptions huge amounts of volcanic gas, aerosol droplets, and ash are injected into the stratosphere. Injected ash falls rapidly from the stratosphere -- most of it is removed within several days to weeks -- and has little impact on climate change. But volcanic gases like sulfur dioxide can cause global cooling, while volcanic carbon dioxide, a greenhouse gas, has the potential to promote global warming.
answer:
a - decrease in the suns energy.
explanation:
although the other options do discuss climate, temperature, etc., the sun DIRECTLY influences the earth's climate and would most likely affect it on a larger scale. for example, warm and cold ocean currents would affect the temperature of the ocean and could touch bay cities or islands, but they would not dictate the overall climate of the earth :)
♡ hopefully my reply helped you come to an answer~ please keep in mind that my response is purely that... MY response! i still have lots to learn, so please correct/educate me if you have found otherwise ♡
Which kind of bond would occur between sodium (Na, Group IA) and chlorine (Cl, Group VIIA)?
Answer:
ionic
Explanation:
I'll put the rest if the answers in comments
Answer:
1. Metallic bonds are responsible for many properties of metals, such as conductivity. Why is this possible?
*The bonds can shift because valence electrons are held loosely and move freely.*
2. Between which types of elements do ionic bonds occur, and how do electrons act within the bond?
*metals and nonmetals, electrons transferred*
3. Which kind of bond would occur between sodium (Na, Group IA) and chlorine (Cl, Group VIIA)?
*ionic*
4. Which type of bond and how many bonds would occur as carbon dioxide (CO2) is formed from carbon in Group IVA and oxygen in Group VIA?
*four covalent bonds*
5. How many covalent bonds is nitrogen (Group 5A) likely to form?
*three*
These are all the answers to the Bonds Quick Check.
Tenemos una disolución de HNO3 cuya pureza es del 65% y tiene una densidad de 1.32 g/mL. ¿Cuál es la molaridad de la disolución? PM HNO3 = 63.0 g/mol.
Teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, la molaridad de la disolución de HNO₃ es 14.67 [tex]\frac{mol}{L}[/tex].
El porcentaje en masa o en peso de una disolución es el número de gramos de soluto que hay por cada 100 gramos de disolución.
Entonces una pureza de 65% indica que hay 70 g de HNO₃ puro por cada 100 g de HNO₃ impuro.
Por otro lado, la densidad es la relación entre el peso o masa de una sustancia y el volumen que ocupa esa misma sustancia.
Entonces, si la disolución de HNO₃ tiene una densidad de 1.32 g/mL (equivalente a 1320 g/L), donde la cantidad de masa es impura, se puede obtener la cantidad de masa de HNO₃ presente 1 L de la solución mediante el siguiente cálculo:
[tex]\frac{1320 g HNO_{3} impuro}{1 L}x \frac{70 g HNO_{3}puro}{100 g HNO_{3}impuro}= 924 \frac{g HNO_{3}puro}{L}[/tex]
Finalmente, la masa molar de HNO₃, es decir la masa presente en un mol de la sustancia, es 63 [tex]\frac{g}{mol}[/tex].
Entonces, teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, es posible determinar la molaridad como:
[tex]\frac{924 g HNO_{3}puro}{L}* \frac{1 mol}{63 g}= 14.67 \frac{mol}{L}[/tex]
En resumen, la molaridad de la disolución es 14.67 [tex]\frac{mol}{L}[/tex]
Aprende más sobre la molaridad:
https://brainly.com/question/17647411?referrer=searchResultshttps://brainly.com/question/21276846?referrer=searchResultswhy do we shake syrup medicines before drinking
Answer:
The label may instruct you to shake a liquid medicine before using so that the active ingredients are evenly distributed throughout it.
Explanation:
Answer:
maybe because if somehow the liquids get separated then shaking them up would mix them back to how they are suppose to be originally.
Explanation:
If a pile of a deson of Buttons has a height of 2cm 4mm, what is the thickness of one to button.
The thickness of one button will be 2mm
According to this question, a pile of a dozen buttons has a height of 2cm 4mm. A dozen means 12, hence, 12 buttons has a height of 2cm 4mm.* N.B: We convert the height of the 12 buttons to same unit (mm)
Since 1cm = 10mmThen, 2cm = 2 × 10 = 20mm
20mm + 4mm = 24mm
That is, twelve buttons (a dozen) has a thickness of 24mm, one button will therefore, be:24/12 = 2mm thick
Hence, one button is 2mm thick.
Learn more at: https://brainly.com/question/3183250
[tex]v=0.164m*8.3cm*12.4cm[/tex]
Answer:
helloooo
0.164m * 100 = 16.4 cm
now multiplying all of em
v = 1,687.888
what is chemistry?????
Answer:
chemistry - the science that studies the properties of substances and natural fenomens .
...........
Answer:
The Basic definition of Chemistry is:-
Chemistry is the scientific study of the properties and behavior of matter. It is the natural science that covers the elements that make up matter to the compounds that is composed of atoms, molecules and ions.
why does an endothermic reaction require a greater activation energy than an exothermic one?
Answer:
in most of the endothermic reactions the atoms gains electrons from one to another. since the atom gains electrons there is a electron repulsive force between the host and the guest electron . As stability is inversely proportional to electron repulsive force the atom gains energy to attain stability .
The endothermic reaction mostly come under electron affinity
Explanation:
hope this helps you
if I am wrong just correct me
sodium chloride + water = ?
which product will it form,and in which phase is it?
Water molecules pull the sodium and chloride ions apart, breaking the ionic bond that held them together.
Must click thanks and mark brainliest
Question 10 of 10 A certain seed is surrounded by a sticky coating. It is fairly dense and does not float in water. How is this seed most likely spread?
A. It is dispersed by the wind, and it sprouts after it falls to the ground
B. It drops to the bottom of a body of water, where it sprouts.
C. It attaches to the fur of an animal, and it sprouts after it falls from the animal's fur.
D. Animals eat it, and it is deposited in their waste.
Classify the crystalline solids
full answer
crystalline solids are the type of solid which have long term arrangement of particle
they have sharp melting and boiling point
Answer:
OMG wow thankyou so so so much for the thanks ( ◜‿◝ )♡
for every __sodium ions transported ___postassium ions are transported
Answer:
In fact, in many neurons three sodium ions are transported for every potassium ion; sometimes the ratio is three sodium ions for every two potassium ions, and in a few neurons it is two sodium ions for one potassium ion.
Our burning of fossil fuels for energy poses several different problems. Describe what is generally considered the biggest problem and the main reason for using alternatives.
PLEASE HELP!!
Which of the following is true of science? (2 points)
It can be disproven by philosophy and religion.
It does not change after new evidence is discovered.
It is based on the personal opinions of scientists.
It is based on testable and replicable evidence.
Answer:
It is based on testable and replicable evidence.
I need help with b) c) and what is the electronic configuration of atom E
Answer:
(b) A and C belongs to same group.
(c) D is a non metal.
Explanation:
The Electronic Configuration of E is
[tex]1s {}^{2} 2s {}^{2}2p {}^{6} 3s {}^{2} 3p {}^{6} 4s {}^{2} [/tex]
Noble gases are the least reactive elements on the periodic table.
A. True
B. False
Answer:
The statement is True!"Why?"The Noble Gases have eight valence electrons, which fill their outer energy level. This is the most stable arrangement of electrons, so noble gases rarely react with other elements and form compounds.
Hope this helps!
A cylinder container with a diameter of 23.0 cm and a height of 140 cm contains N2O at a pressure of 108 kpa and temperature of 294 K. How many grams of N2O gas are in the cylinder?
Answer:
113.17 g
Explanation:
This can be solved using the Ideal Gas Equation:
PV=nRT
First step is to calculate the volume of the cylinder in L:
V=πr²h
V= π (11.5)² (140)
V= π (132.25) (140)
V = π (18.515)
V = 58,166.588 cm³ = 58.2 L
Then, convert kpa into atm:
1 kpa = 0.00987 atm
108 kpa = 1.06588 atm
Then, plug all of your values into the Ideal Gas Equation to solve for moles:
(1.06588)(58.2)=n(0.082057)(294)
62.034=n(24.125)
2.571357513=n
Finally, convert the moles into grams
2N = 28.0134 amu
O = 15.999 amu
_______________
44.0124 amu
(2.571357513moles)(44.0124 amu) = 113.17 g
Can someone plz help me :<
Answer: cats r alliens because they r kind of like ufos they would usually wonder around rather u know it or not when they spy on us it could b with us sleep cooking anything so they r like aliens
Explanation:
Why doesn’t the KHP concentration have to be exactly 0.100M? Explain using complete sentences.
Answer:
The answer is in the explanation.
Explanation:
The KHP is an acid used as standard in titrations to find concentration of bases as NaOH.
The reaction that explain this use is:
KHP + NaOH → KNaP + H2O
where 1 mole of KHP reacts per mole of NaOH
That means, at equivalence point of a titration in which titrant is NaOH, the moles of KHP = Moles of NaOH added
With the moles of KHP = Moles of NaOH and the volume used by titrant we can find the molar concentration of NaOH.
The moles of KHP are obtained from the volume and the concentration as follows:
Volume(L)*Concentration (Molarity,M) = moles of KHP
If the concentration is more or less than 0.100M, the moles will be higher or lower. For that reason, we need to know the concentration of KHP but is not necessary to be 0.100M.
WILL MARK BRAINLIEST IF YOUR ANSWER IS CORRECT
Answer:
1. Element
2. Compound
3. Heterogeneous mixture
4. Homogeneous mixture
5. Homogeneous mixture
6. Heterogeneous and homogeneous mixture
7. Homogeneous mixture
8. Heterogeneous mixture
