These are reactions that transfer energy to the surroundings (ie the energy exits from the reaction, hence the name exothermic). The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to become hotter. A thermometer is used to detect the temperature increase.
Examples:
Combustion
Neutralisation between acids and alkali
Endothermic reactionsThese are reactions that take in energy from the surroundings (ie energy enters the reaction, which will help you to remember the name endothermic). The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to become colder. A thermometer is used to detect the temperature decrease.
Example:
Electrolysis
The energy associated with a current is called____________
(A) mechanical energy
(B) magnetism
(C) geothermal energy
(D) electrical energy
Answer:
D. Electrical energy
Explanation:
I assume you are talking about an electrical current.
(These are by what I know and are simplified, not an exact definition)
A. Mechanical energy is energy that something has because of motion.
B. Magnetism is the attracting and repulsing forces between magnets.
C. Geothermal energy is heat inside of the Earth. Used as source of power.
D. Electrical energy is the result of an electric charge.
Which one of the following ionic solids would have the largest lattice energy?
CaBr2
CsI
CaCl2
NaCl
NaF
Answer:
CaCl2
Explanation:
The ionic solid CaCl₂ would have the largest lattice energy. Therefore, option (c) is correct.
What is the lattice energy?Lattice energy is the heat of formation when one mole of crystalline ionic solid is generated from its constituent ions in their gaseous state.
For example, the lattice energy of sodium chloride crystal is the energy change of reaction when Na⁺ and Cl⁻ ions react to produce a NaCl crystal, which is equal to -786 kJ/mol.
The relation between lattice energy and lattice enthalpy at constant pressure is given by:
ΔU (lattice) = ΔH (lattice) - PΔV
Lattice energy is directly proportional to the charge on ions and inversely proportional to the interionic distance between ions.
For NaCl and NaF the charge on the ions is +1 and -1 while the size of the ions is small. So they have less lattice energy.
CsI ionic solid have a larger size of ions Cs⁺ and I⁻. So CsI will have less lattice energy. CsBr₂ has +2 charge on calcium but the size of both ios is larger. So, CsBr₂ will have less lattice energy.
CaCl₂ has + 2 charge on calcium as well as the ionic radius is also samll. Therefore, CaCl₂ would have the largest lattice energy.
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C5H12 + O2 = CO2 + H2O
If 84.3 grams of C5H12 react according to the above equation and the % yield is 94% find the actual yield of grams of carbon dioxide
Answer: 241.6 grams of CO2
Explanation: you take 84.3 grams C5H12 and divide it by 72.15 grams of C5H12(which is the molar mass) you take that answer and calculate the mols of CO2 by multiplying the 1.168 you got before and multiply it by 5. You take the answer you get from that and multiply it by the molar mass of CO2 and get the theoretical yield and then you just plug it in. 94= (x/257.02)x100 and solve to find x which is the actual yield.
determine the empirical and molecular formulas of a compound that gives the following analysis in math percent: 24.27% C,4.07% H, and 71.65%CL. the molar mass is known to be 197.92g/mol.
Answer:
help me with this
Explanation:
13. What is the meaning of the word faint?
how does bases taste?
Answer:
bases taste bitter, feel slippery, and conduct electricity when dissolved in water
Explanation:
Answer:
like peas
Explanation:
Which statement describes an interaction between the biosphere and the atmosphere that is related to
photosynthesis?
• During photosynthesis, plant roots take in water from soil.
O During photosynthesis, plants take in carbon dioxide from the air.
O Through photosynthesis, energy stored in plants is released into the air.
O Through photosynthesis, energy stored in plants is transferred to humans who eat them
Answer:
O During photosynthesis, plants take in carbon dioxide from the air.
Answer: The answer is: During photosynthesis, plants take in carbon dioxide from the air.
Explanation: I have my ways ;>
Can someone please help me with this question?
es 3l por 0/0 (1234008×556098
Which periodic table has the elements placed in locations that match the information on the flash card?
Answer:
https://quizizz.com/admin/quiz/5902a3fd8d05b2100088880a/cat-1-chemistry-review
Explanation:
Answer:
atomic? hope this helps!
Explanation:
Elements are solid liquid and gas substance that can be found on earth which statements best describes an element
Answer:
i guess
Explanation:
we will never know
An atom of carbon contains 6 total electrons. How many of these electrons are in s orbitals?
1
2
4
6
Answer:
4
Explanation:
total electrons = 6
electronic configuration = 1s^2, 2s^2, 2p^6
so in s orbital there are 4 electrons.
Hope it helps you (｡◕‿◕｡)
What would be an inference you could make about this cat?
Answer:
pickles are ligit good
Explanation:
i like pickles but not his
Hypothesis: What do you think will happen when you add more magnets to the set up?
Answer:
........................
why are oxidation numbers assigned to the elements before writing a chemical formula
Answer:
Oxidation numbers assign ownership of the electrons to one atom or another in a compound. ... Scientists use these numbers to help name compounds, write formulas and balance chemical equations. They are also useful when studying reactions and they can help you identify when something is oxidized or reduced.
How many moles are there in 1.20 x 1025 particles of helium?
Answer:
You would get 19.969 moles.
Explanation:
You would get 19.969 moles.
An artificial reef is intended to affect the ocean ecosystem by — А A removing pollution from the water B В providing shelter for marine organisms causing sediment to erode into deeper waters D preventing people from overfishing along the shore
Answer:
B
Explanation:
just answered
An artificial reef is intended to affect the ocean ecosystem by providing shelter and habitat for marine organisms causing sediment to erode into deeper waters. Hence, option C is correct.
What is artificial reef ?An artificial reef is a human-made underwater structure, typically constructed with the purpose of enhancing marine biodiversity, providing habitat for marine organisms, and promoting recreational activities like fishing, diving, and snorkeling.
Artificial reefs can be created from a variety of materials, such as concrete, metal, tires, and sunken ships. The reef structure can also increase the overall biodiversity of an area by creating a new habitat for species that may not have been present before.
Additionally, the presence of an artificial reef can help to reduce pressure on natural reefs by providing an alternative location for fishing and other activities. However, artificial reefs are not typically used as a means of removing pollution from the water or preventing erosion.
Therefore, option C is correct.
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A 57 g g sample of iron reacts with 24 g g of oxygen to form how many grams of iron oxide?
A 57 grams sample of iron reacts with 24 grams of oxygen to form 81 grams of iron oxide.
What is iron oxide?
Iron oxide is a chemical compound that is made by the addition of iron and oxygen can also be known as ferrous oxide if react with two oxygen molecules then ferric oxide.
In the sample, the iron is 57 grams and the oxygen is 24 grams,
Fe + O -------------> FeO
Iron oxygen iron oxide
By adding the mass of iron and oxygen,
57 + 24 = 81 grams of iron oxide.
Therefore, the mass of iron oxide is 81 grams if 57 grams sample of iron reacts with 24 grams of oxygen.
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look at the four chemical reactions
reaction 1:4Na + O ▾ 2 -->2Na ▾ 2O
Reaction 2: 2NaCl—> 2Na+Cl ▾2
reaction 3: CaCO ▾3 —> CaO +CO ▾2
reaction 4: 2KCIO3 ▾3 —> 2KCI + 3O ▾2
which statement identifies the reaction that is different from the rest and explains correctly why it is different?
A.) Reaction 2, because two ions are interchanged
B.) Reaction 2, because two products are formed
C.) Reaction 1, because a single product is formed
D.) Reaction 1, because a single ion is replaced in a compound
Reaction 1 is the one that is different because there is only one product (option C).
In a reaction, there are two main components:
The reactants: Substances at the beginning of the reaction.The products: Substances at the end of the reaction.Moreover, a reaction can include two or more reactants as well as two or more products depending on the substances involved. Let's analyze reaction 1:
Reaction 1: 4Na + O2 → 2Na2OReactants: 4Na and O2Product: 2Na2OThis means in this reaction there is only one product. This does not occur in reactions 2, 3, and 4 because in these there are two products.
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 how are subscripts determine the formula of ionic and covalent compounds ?
Answer:
To determine the correct subscripts in a chemical formula, you have to solve how many atoms you need to balance the charge.
For example if I had the compound Calcium Fluoride I would look at the periodic table and see that Calcium's ionic formula is
Ca2+
. How do I know this? Well all elements want to have 8 valance electrons so they can be stable(happy). Seeing that Calcium has 2 valance electrons it is going to give away 2 electrons because that is easier than gaining 6 to be happy. Since Calcium has given away 2 electrons it has two more protons than electrons. We know that Protons have a Positive charge, Electrons have Negative charge, and the number of electrons is equal to the atomic number of an element in its pure non-ionic state. (Meaning it doesn't have a positive or negative charge; it is balanced.)
So if calcium gave away two electrons, it will have two more protons than an electron giving it a (2+) charge. The same process can be applied to Fluoride. Since fluoride is one to the left of the noble gases(group 18 or 8A) on the periodic table we know that it has 7 valance electrons because it is in group 7A or 17.
Knowing that we have 7 electrons the fluoride atom will gain an extra electron. Since the fluoride atom gained an extra electron it will have one more negative charge than a positive making it a ^(−)ion.
So you know that Calcium has a 2+ charge and that fluoride has a 1- charge, you then need these ions to balance out. So you need two fluorine atoms with a 1- ions to balance out the 2+ ion of calcium. Your final answer would be
CaF2
because you need two fluorine atoms to balance out the 2+ charge of the calcium.
Final Tip: Determine the charges then inverse the charges, remove the positive and negative superscipts, and write the charge numbers as a sub script. Ie. Calcium Fluoride
Ca2+ and F−
inversing and removing the charge signs would give you
In a graph, what effect would adding a catalyst have on D?
A. It would decrease.
B. It would increase.
C. It would stay the same.
D. You cannot tell from this graph.
Answer:
C. It would stay the same
Explanation:
PLATO answer
pls help
Plot the point (5,9)
How much water has to be evacuated from 250ml of 1M Ca(OH)2 to make it 3M
Answer:
ERROR
Explanation:
Answer could not be show due to technical difficulties
The concentration terms are molality, normality and mole fraction. Molarity can be used to find out the ionic strength of any solution. The volume of 3M diluted solution of calcium hydroxide is 83.3ml.
What is molarity?Molarity can be calculated by dividing number of moles of solute by volume of solution in litre. Molarity is affected by temperature. Its unit is mole/liter. It measure the concentration of any solute in a solution.
Mathematically,
According to the neutralization law,
M₁V₁=M₂V₂
where,
M₁ = molarity of stock solution = 1 M
V₁ = volume of stock solution = 250ml
M₂ = molarity of dilute solution =3M
V₂ = volume of dilute solution = ?
substituting all the given values we get
M₁V₁=M₂V₂
1 M×250ml=3M×V₂
V₂=83.3ml
Therefore, volume of 3M diluted solution of calcium hydroxide is 83.3ml.
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Can someone help me over here? I need an negative charge and also another thing is that in a question it asked me to use something that would represent an ion. I’m not sure on what to choose either Hydrogen or Helium but just please send help.
Answer:
You could use a hydrogen anion which has 2 electrons.
Explanation:
An ion is an atom or molecule with a net electric charge because it has more or less electrons compared to the original atom or molecule.
An anion is a negatively charged ion.
A cation is a positively charged ion.
Normally a hydrogen atom has one proton and one electron.
So a hydrogen anion (H-) means that it has one proton and two electrons, which means the positive charge will be +1 and the negative charge will be -2.
Ultimately, giving the entire molecule a net charge of -1 because -2+1 = -1.
(I hope this helps! I am not 100% sure what's the format of this question. Like is it interactive? online? Did you draw all those electrons on the diagram? or were they given? Are the numbers given as well? or did you type those in? So I just tried my best to give you something that might work.)
A chemist prepares a solution of silver(I) perchlorate by measuring out of silver(I) perchlorate into a volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's silver(I) perchlorate solution. Be sure your answer has the correct number of significant digits.
The question is incomplete, the complete question is;
A chemist prepares a solution of silver (I) perchlorate (AgCIO4) by measuring out 134.g of silver (I) perchlorate into a 50.ml volumetric flask and filling the flask to the mark with water. calculate the concentration in mol/L of the silver (I) perchlorate solution. Round your answer to 2 significant digits.
Answer:
13 mol/L
Explanation:
We must first obtain the number of moles of silver I perchlorate involved
Molar mass of silver I perchlorate = 207.32 g/mol
Number of moles of silver I perchlorate = 134g/207.32 g/mol = 0.646 moles
Recall that;
n =CV
C= concentration
V= volume
n = number of moles
C = n/V
C = 0.646 moles * 1000/50
C = 13 mol/L
WILL GIVE BRAINLIEST!!!
Use this media to help you complete the question.
There are three known forms of hydrogen. These forms are called (isotopes, ions, copies) of each other. Each of these forms will have the same number of (neutrons, protons, electrons) but different numbers of (neutrons, protons, electrons) in their nuclei.
Answer:
Isotopes, protons, netrons
Explanation:
Answer:
There are three known forms of hydrogen. These forms are called Isotopes of each other. Each of these forms will have the same number of protons but different numbers of neutrons in their nuclei.
Explanation:
True or False:
Houston, Texas received approximately 2 inches of snow on February 15, 2021. Based on this, we can now say Houston's climate consists of long, freezing winters and yearly snowfall. Please answer ASAP. Thanks
Answer:
False.
Explanation:
I majored in Chemistry
Jewelry and tableware are sometimes made of sterling silver. Sterling silver is 92.5% silver (Ag) and 7.5% copper (Cu). If you wanted to make 30 grams of sterling silver for a ring, how many grams of silver and copper would you need to start with?
Amount of sterling silver?
Amount of copper?
total grams of alloys needed?
Answer:
12.33
Explanation:
92.5/7.5= 12.33
30g of the sterling silver ring contains, 27.75 g of silver and 2.25 g of copper.
What is cross multiplication?Cross multiply fractions by multiplying one fraction's denominator by the other fraction's numerator and then comparing the two values. The larger fraction is the one with the higher value.
100g of sterling silver contains 92.5g of silver and 7.5g of copper.percentage of element = amount of the element present in 100 g of materialTherefore,
100g sterling silver = 92.5g silver30g sterling silver = X g silver( cross multiplication),
100 × X = 92.5 × 30
X = 92.5 × 30/ 100
X= 27.75g silver100g sterling silver = 7.5g copper
30g sterling silver= Y g copper
(cross multiply)
100 × Y = 7.5 × 30
Y= 7.5 × 30 / 100
Y= 2.25g copperX (silver)= 27.75 g in 30 g of sterling silverY (copper)= 2.25 g in 30 g of sterling silvertherefore, 30g of sterling silver ring contains, 27.75 g of silver and 2.25 g of copper.
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why is eating fruits and vegetables always included in the lists of prevention for malnutrition and micronutrients deficiencies
Pls help I’ll mark brainliest pls pls pls
Answer:
the tea was not hot sugar dissolves quickly and hot water than cold
1.I make my cup of coffee in the morning by pouring boiling water over ground-up coffee beans held in a special piece of paper and by collecting the brown liquid that comes through. Which techniques of the five described in the background section is/are used in the preparation of the cup of coffee
Answer:
Filtration
Explanation:
Filtration is a physical separation technique that is used to separate solids from liquids or gases. The process involves the use of a filter which allows just the liquid to pass through.
In this case, the coffee beans is the solid and the boiling water is the liquid. The special piece of paper is the medium (filter) through which the coffee is collected.
The coffee coming through the special piece of paper (filter) is called a filtrate.
Filtration is used in the preparation of the cup of coffee.