Exothermic reaction is where there is release of energy during a reaction
The enthalpy of exothermic reaction is negative
The relation between energy of products, reactants and enthalpy of reaction is
Enthalpy of reaction = sum of enthalpy of formation of products - sum of enthalpy of formation of reactants .
As enthalpy of reaction is negative, it means the enthalpy of products is less than the enthalpy of reactants so answer is :
In an exothermic reaction the energy of the product is less than the energy of the reactants.
C.
An endothermic reaction is a reaction that absorbs heat from the surroundings. That means that the energy of the system must increase. Therefore, the answer must be C as the products should have higher energy than the reactants.
Which correctly lists three items that are removed during the purification of wastewater?
chemicals, gases, solids
debris, chemicals, solids
gases, debris, groundwater
groundwater, gases, harmful organisms
Answer: its the 3rd one
Explanation:
Answer:
gases, debris, groundwater.
Explanation:
if I'm wrong blame me.
hope it helps.
and can I have briniest
Will calcium metal react with chromium (III) chloride? Explain your answer
Calcium metal with chromium(III) chloride would react. Calcium metal is more reactive than chromium metal; therefore, putting calcium metal in chromium chloride would create a reaction, where as putting chromium metal in calcium chloride would not form any reaction.
what element has 12 protons 12 neutrons and 11 electrons
Answer:
sodium atom
Explanation:
How many grams of oxygen would be contained in 4.00 L at 158kPa and 28 C?
Answer:
it would be 53
Explanation:
because 4.00 L at 158kPa and 28c would be 53 grams of oxygine
What mass of sugar and water is needed to make 40 g of 10% solution?
Answer:16g
Explanation:A solution's percent concentration by mass,
% w/w
, basically tells you what mass of solute you get per
100 g
of solution.
1. While on a movie set, a stuntman jumps off
the roof of a building. As he falls toward an
airbag, what is increasing?
A. gravity
B. wind velocity
C. kinetic energy
D. potential energy
kinetic energy kkkkkkkkkk
an atom of which of the following elements can form the most bonds?
a. phosphorus
b. sodium
c. oxygen
d.oxygen
What happens during
conduction?
A. The warmer object's particles slows
down the cooler object's particles.
B. The warmer object's particles stops the
cooler object's particles.
C. The warmer object's particles speed up
the cooler object's particles.
Answer: the answer is C. The warmer object's particles speed up
the cooler object's particles.
Explanation: Conduction occurs when a substance is heated, particles will gain more energy, and vibrate more. These molecules then bump into nearby particles and transfer some of their energy to them. This then continues and passes the energy from the hot end down to the colder end of the substance.
How many elements are present in the compound Na_2S_2O_3
Answer:
3 elements are present in thr compound
Use the Periodic Table to find molar mass of water. Sodium hydroxide (NaOH) and hydrochloric acid (HCl) react to form sodium chloride (NaCl) and water according to the equation: NaOH HCl → NaCl H2O What mass of water forms when 2. 75 Ă— 10â€""4 mol NaOH reacts completely? 2. 75 Ă— 10â€""4 mol NaOH = g H2O.
Considering the reaction stoichiometry, 0.00495 grams of water is produced when 2.75×10⁻⁴ moles of NaOH reacts completely.
Sodium hydroxide (NaOH) and hydrochloric acid (HCl) react to form sodium chloride (NaCl) and water. So, the balanced reaction is:
NaOH + HCl → NaCl + H₂O
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
NaOH: 1 moleHCl: 1 moleNaCl: 1 moleH₂O: 1 mole
In the periodic table, you can find the molar mass of the elements, also called atomic mass or atomic weight. So, to calculate the molar mass of a compound, you must add the molar mass of the elements of the compound multiplied by the times they appear in the compound.
So, in the case of water:
H₂O= 2× 1 g/mole + 16 g/mole
H₂O= 18 g/mole
Then, if by stoichiometry of the reaction 1 mole of water is produced, the mass of water produced is calculated as:
mass H₂O= 1 mole× 18 g/mole
mass H₂O= 18 g
Then you can apply the following rule of three: if by stoichiometry 1 moles of NaOH produce 18 grams of H₂O, 2.75×10⁻⁴ moles of NaOH will produce how much mass of H₂O?
[tex]mass of H_{2} O=\frac{2.75x10^{-4} moles of NaOHx18 grams of H_{2} O}{1 mole of NaOH}[/tex]
mass of H₂O= 0.00495 grams
In summary, 0.00495 grams of water is produced when 2.75×10⁻⁴ moles of NaOH reacts completely.
Learn more about stoichiometry:
brainly.com/question/16487206?referrer=searchResults brainly.com/question/14446695?referrer=searchResults brainly.com/question/11564309?referrer=searchResults brainly.com/question/4025026?referrer=searchResults brainly.com/question/18650135?referrer=searchResultsIn the TCA cycle, ____ oxidation(s) use(s) NAD as the oxidizing agent while ____ oxidation(s) use(s) FAD as the oxidizing agent.
Tricarboxylic acid cycle often occur in stages. In the TCA cycle, 3 oxidation(s) use(s) NAD as the oxidizing agent while 1 oxidation(s) use(s) FAD as the oxidizing agent.
Tricarboxylic acid cycle commonly called TCA cycle is also regarded as the Krebs cycle and citric acid cycle. It is known to be the second stage of cellular respiration.It consist of a three-stage process where living cells uses organic fuel molecules in the presence of oxygen to take-up energy that is needed for growth and division.
See full question below
In the TCA cycle, ____ oxidation(s) use(s) NAD + as the oxidizing agent while ____ oxidation(s) use(s) FAD as the oxidizing agent.
a. 0; 4
b. 1; 3
c. 2; 2
d. 3; 1
e. 4; 0
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oxygen is odorless and colorless physical or chemical
Answer:
(Physical or Chemical) properties of a substance can easily be observed. … (Physical or Chemical) properties can be used to identify substances. physical property. Oxygen is odorless and colorless.
Explanation:
Which is the correct definition of electronegativity?
Answer:
Electronegativity is defined as the tendency of an atom participating in a covalent bond to attract the bonding electrons
Explanation:
Electronegativity increases and you go up and to the right, making fluorine the most electronegative element.
What is held together by a metallic bond?
Answer:
metallic bond, force that holds atoms together in a metallic substance. The atoms that the electrons leave behind become positive ions, and the interaction between such ions and valence electrons gives rise to the cohesive or binding force that holds the metallic crystal together.
Explanation:
write a balanced equation for the formation of co2 g from c s and o2 g
Answer:
C (s) + O2 (g) > CO2 (g)
That's what I got
Help!! I’ll mark you Brainliest.!
Answer:
For 5 pts? gimme that
Explanation:
Answer:
Explanation:
if you know what those phrases mean, then you can look them up and draw those pictures you find, as well as add the definition of each.
carbon-14 has a half-life of 5,730 years. how long will it take for 112.5 g of a 120.0-g sample to decay radioactively?
Answer:
It will take 22920 years to decay 112.5 g of 120 grams.
Explanation:
A sugar crystal contains approximately 1.4×1017 sucrose (C12H22O11) molecules. What is its mass in milligrams? Express using 2 sig figs
Answer:
Our process would be just turning the molecules of sucrose to the moles by dividing using Avogadro's number (6.02 x 10^23), which will give us the moles we need. In order to find the mass of the sucrose, you have to multiply the moles by the molar mass of sucrose in order to find the mass, and then multiply by it 1000 to change it to mg.
Here are the formulas:
Number of moles = Number of molecules / Avogadro's number
Mass = Moles x Molar mass
Number of moles = (1.4 x 10^17) / (6.02 x 10^23) = 2.3255814 x 10^-7 moles
Now that we have the moles, we can multiply them by Sucrose's molar mass, which can be calculated by using the masses listed in the periodic table.
Carbon's Molar Mass = 12g/mol (There are 12 atoms of Carbon in sucrose)
Hydrogen's Molar mass = 1.01g/mol (22 atoms of Hydrogen in sucrose)
Oxygen's Molar mass = 16g/mol (11 atoms of oxygen in sucrose)
Now we just add them together:
((12)x(12)) + ((1.01)x(22)) + ((16)x(11)) = 342.22g/mol is the molar mass of Sucrose
Now back to the question, you multiply the moles of sucrose by its molar mass to get the mass in grams
(2.3255814 x 10^-7) x (342.22) = 0.0000796 grams
Now to get it in milligrams, you multiply the answer above by 1000
0.0000796 x 1000 = 0.079 mg (already in 2 sig figs)
Therefore there are 0.079 milligrams of sucrose in the sugar crystal.
The mass of sucrose molecules is 0.079 milligrams .
How is mass calculated from number of molecules?To calculate mass of a substance wherein number of molecules is given, initially number of moles is obtained.
number of moles= number of molecules/Avogadro's number
=1.4×10¹⁷/6.022×10²³
=2.234×10[tex]^-7[/tex]
Now the mass is calculated by multiplying number of moles into molar mass of sucrose
=2.234×10[tex]^-7[/tex]×342.22
=795.31 ×10[tex]^-7[/tex] g
=0.079 mg.
The mole concept is a convenient method for expression of amount of substance in chemical applications.It is mainly focused on the quantity of mole which is a count of large number of particles.One mole of any substance is equal to the Avogadro's number .
It is useful for measuring products of chemical reaction. It is the basis of stoichiometry and expresses amount of reactants and products which are formed and consumed during the course of chemical reaction.
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Help answer these chemistry questions
Answer:
45th answer is pure and properties 42 is periodictable
What’s clues indicate that a chemical reaction has occurred?
Answer:
Color change, formation of bubbles, and temperature change
The percent of attacks on the dark-colored mouse models is how many times greater than the percent of attacks on light-colored models
The number of times the percentage of attacks on the dark-colored mouse is greater than the percentage of attacks on light-colored mouse is four (4) times.
Let the percent of attacks on the dark-colored mouse be D.Let the percent of attacks on light-colored mouse be L.Given the following data:
Light-colored mouse models = 20 percentDark-colored mouse models = 80 percentTo determine the number of times the percentage of attacks on the dark-colored mouse is greater than the percentage of attacks on light-colored mouse.
Therefore, we would simply divide the percentage for the dark-colored mouse by the percentage for the light-colored mouse as follows:
[tex]Number \;of\;times = \frac{D}{L}[/tex]
Substituting the given parameters into the formula, we have;
[tex]Number \;of\;times = \frac{80}{20}[/tex]
Number of times = 4 times.
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if the atoms that share electrons have an unequal attraction for the electrons, the bond is called
Answer:
A polar covalent bond is a covalent bond in which the atoms have an unequal attraction for electrons and so the sharing is unequal. In a polar covalent bond, sometimes simply called a polar bond, the distribution of electrons around the molecule is no longer symmetrical.
Explanation:
Consider the following system at equilibrium. CaCO3(s) Double headed arrow. Ca2 (aq) CO32â€""(aq) The addition of which compound will cause a shift in equilibrium because of a common ion effect? CCl4 CO2 CuSO4 Na2CO3.
The compound that has been capable to shift the equilibrium with common ion effect has been [tex]\rm \bold{Na_2CO_3}[/tex]. Thus, option D is correct.
The complete equation for the decomposition of calcium carbonate has been:
[tex]\rm CaCO_3\rightleftharpoons Ca^2^+\;+\;CO_3^2^-[/tex]
The equilibrium has been the state in the reaction, when the number of products and has been equivalent to the number of reactants. The increase or decrease in the concentration of any of the reactant or product results in the shift in the equilibrium.
For the given reaction, the addition of Calcium or carbonate ions to the solution results in the increase in the product concentration with the common ion effect, and thereby shifts the equilibrium condition.
The ions liberated by the following compounds has been:
[tex]\rm CCl_4\;=\text{not dissolved}\\CO_2\;+\;H_2O\leftrightharpoons CO_3^-\;+\;H^+\\CuSO_4\leftrightharpoons Cu^2^+\;+\;SO_4^2^-\\Na_2CO_3\leftrightharpoons 2\;Na^+\;+\;CO_3^-[/tex]
The compound, that has been capable of liberating the carbonate ions in the medium has been [tex]\rm \bold{Na_2CO_3}[/tex]. Thus, it results in the shift of the equilibrium due to common ion effect. Hence, option D is correct.
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The clouds of Venus consist mainly of ______. Group of answer choices carbon monoxide droplets of water vapor hydrogen and helium droplets of sulfuric acid gaseous nitrogen
Answer:
droplets of sulfuric acid
Explanation:
Elements that are usually dull, brittle and do not conduct electricity are know as______.
Points: 46
Answer:
nonmetal
Explanation:
.........
...
.
Two protons and two neutrons are released as a result of this reaction. Superscript 222 subscript 86. Rn Right arrow superscript 218 subscript 84. Po ? Which particle is released? one alpha particle two beta particles one alpha and one beta particle one high-energy photon.
The particle released in the reaction has been an alpha particle. Thus, option A is correct.
The release of protons and neutrons in a reaction has been nuclear reactions. The reactions results in the change in the atomic mass of the atom, with the formation of new atom. The extra mass has been released in the form of energy.
The release from the given reaction has been:
[tex]\rm ^{222}_{66}Rn\;\rightarrow\;^{218}_{84}Po\;+\;^A_ZX[/tex]
Where, X has been the particles that has been released with the nuclear reaction. The superscript A has been the Mass of particle, and subscript Z has been the atomic number.
According to the law of conservation, the mass has been constant on both the product and the reactant side. Thus, the mass and atomic number of eliminated particles has been given as:
[tex]\rm 222=218+A\\A=222-218\\A=4[/tex]
The atomic mass of the particle has been 4.
[tex]\rm 86=84+Z\\Z=86-84\\Z=2[/tex]
The atomic number of the particle has been 2.
The element with atomic mass 4, and atomic number 2 has been the Helium particles, [tex]\rm ^4_2He[/tex]. It has been an alpha particle. Thus, the particle released in the reaction has been an alpha particle. Thus, option A is correct.
For more information about the particles released, refer to the link:
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Answer:
A
Explanation:
Select all the correct answers.
In the cathode ray tube experiment, J.J. Thomson passed an electric current through different gases inside a cathode ray tube in the presence of
an electric field. In which two ways did this experiment change scientists' understanding of the atom?
O It showed that atoms combine in different proportions.
O It showed that atoms can be divided into smaller parts.
M It showed that all atoms of the same element are similar.
D
It showed that individual atoms could be destroyed
showed that all atoms contain electrons.
The two ways the cathode ray tube experiment changed scientists'
understanding of the atom was it showing that atoms can be divided into
smaller parts and all atoms contain electrons.
J.J Thompson was the scientist which performed the cathode ray tube
experiment and was able to ascertain it was negatively charged as a result
of it being deflected to the positive electrode.
His observation showed that the atoms contain sub-atomic particles called
electrons which are negatively charged.
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has anyone done 4.3.4 Practice: Mixtures of Matter...I need help :/
The types of mixtures are homogeneous and heterogeneous, you can identify these based on their features.
A mixture occurs when two or more materials are mixed or combined. For example, if you combine two or more liquids. Moreover, this can lead to two types of mixtures:
Homogenous mixtures.Heterogeneous mixture.Each of these has defined features that affect the characteristics and properties of a mixture:
Homogenous mixtures:
Once the mixture is done its components cannot be easily identified.The composition is uniform.Some examples include lemonade, smoothy, and concrete.Heterogeneous mixture:
The components can be easily identified and even separated after the mixture.The composition is not uniform.Some examples include salad, pizza and oil mixed with water.Note: This question is incomplete because of this, I answered based on general knowledge.
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What is the main cause of global convection currents?
A. Deforestation
B. The Greenhouse effect
C. The increase in the number of cities
D. Uneven heating of the Earth by the sun
Answer: The answer is D, uneven heating of the Earth by the Sun.
The characteristics “fingerprints” of light produced when a substance is given energy are called…
A. Groundlings
B. Quantums
C. Spectrums
D. Amplitudes
A spectrum is a pattern is unique to a substance and can be used identify it.
According to Max Plank, energy occurs in packets called quanta. Hence, energy is not continuous but takes on discrete values which are integer multiples of a fundamental amount.
Again, when a substance is given light energy, a characteristic fingerprint is obtained. This pattern is unique to the substance that has it. These characteristics “fingerprints” are called spectrums.
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