Answer:
Explanation:
Heat is a reactant.
If the equation requires heat to occur, the reaction is endothermic
The equation would have this model
A + B + heat =====> C + D
If the equation gives away heat, then it is exothermic
The equation would look like this. (I'll use a common reaction)
CH4 + 2O2 - heat ===> CO2 + 2H2O
The heat is minus when it has to be given away.
Why should you prefer dry-ashing to wet-ashing of a food sample such as cabbage?
Answer:
The work was to demonstrate a repaid, precise and accurate determination method for ten trace elements (Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Se and Zn) in periostracum serpentis (PS) and periostracum cicadae (PC) by inductively coupled plasma atomic emission spectrometry (ICP-AES). In order to evaluate the best digestion method, three different sample digestion methods including dry ashing, wet ashing and microwave digestion procedures were compared in this study.
Explanation:
Ice at 0.0 degrees Celsius is combined with 50.0g of water at 75.0 degrees Celsius. Calculate the grams of ice present initially if the entire mixture comes to a final temperature of 25.00 degrees Celsius after the ice melts. Specific heat of water is 4.18 J/g degrees Celsius. SHOW WORK!
Answer:
m-Ice = 23.85g
Explanation:
The heat absorbed for the cold water (Heat of the increase of water + Heat of ice melting) is equal to the heat released for the water at 75°C. The equation is:
m-Ice-*C*ΔT + Hf*-m-Ice = m-water*C*ΔT
Where m-Ice- is our incognite
C is specific heat of water = 4.18J/g°C
ΔT is change in temperature = 25.0°C - 0.0°C = 25.0°C
Hf is enthalpy of fusion of water = 333.6J/g
m-water = 50.0g
ΔT is change in temperature = 75.0°C - 25.0°C = 50.0°C
m-Ice-*4.18J/g°C*25°C + 333.6J/g*-m-Ice = 50.0g*4.18J/g°C*50.0°C
104.5 m-Ice- + 333.6 m-Ice- = 10450
438.1 m-Ice = 10450
m-Ice = 23.85gIf 4.50 moles of C2H6 undergoes combustion, how many moles of oxygen would it combust with?
Answer:
First balance the equation
C2H6 + 7/2O2 2CO2 +3H2O
for one mole of C2H6 there are 7/2 mole of O2 required. so for4.50 moles you require 4.50 x 7/2 = 15.75 moles of O2.
Explanation:
A gas in a sealed container has a pressure of 125 atm at a temperature of 303 K. If the pressure in the container is increased to 200 atm, what is the new temperature if the volume remains constant?
(Show work pls :)!)
Answer:
485 K
Explanation:
Step 1: Given data
Initial pressure (P₁): 125 atmInitial temperature (T₁): 303 KFinal pressure (P₂): 200 atmFinal temperature (T₂): ?Step 2: Calculate the final temperature of the gas
Assuming constant volume and ideal behavior, we can calculate the final temperature of the gas using Gay Lussac's law.
P₁/T₁ = P₂/T₂
T₂ = P₂ × T₁/P₁
T₂ = 200 atm × 303 K/125 atm = 485 K
HNO3 + NaOH → NaNO3 + H2O
Answer:
Explanation: what is the question?
This is a neutralisation reaction.
What is the function of an atoms nucleus?
1. It holds protons and
neutrons
2. It contains electrons
3.it communicates with other atoms
4.none and above
Answer:
The answer to the question is A. :)
The correct answer is Option A.
Protons and neutrons are found in the nucleus.
Explain about atoms nucleus?An atom is a complex configuration of negatively charged electrons arranged around a positively charged nucleus in predetermined shells. Electrically positive protons and electrically neutral neutrons make up atomic nuclei. The strongest fundamental force known to science, also known as the strong force, holds these things together. The nucleus typically makes up more than 99.9% of the atom's mass but much less than.01 percent of its volume.Although protons and neutrons are similar in mass, protons have one unit of positive charge (+ e), while neutrons have no charge. The center of an atom is where all of these particles are crammed into a very small area.The force needed to keep an atom together and in place is produced by the atom's nucleus.To learn more about atoms nucleus refer to :
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What type of reproduction occurs in members of the bacteria kingdom?
Answer:
Bacteria can use sexual and asexual repoduction
Explanation:
Balance the following equations:
1) C2H402+_02->_C02+ _H20
2) V205+ _CaS→_Ca0+ V2S5
3) S8+_O2->_SO2
Answer:
1) 0 C2H4O2 + 0 O2 -> 0 CO2 + 0 H2O (balanced)
2) V2O5 + CaS -> CaO + V2S5
just additional info: V2O5 is divanadium pentaoxide
LHS (Left hand side)
V: 2
O: 5
Ca: 1
S: 1 x 5 [to balance with the right hand side of the equation]
RHS (Right hand side)
V: 2
O: 1 x 5 [to balance with the left hand side of the equation]
Ca: 1
S: 5
When you balance any elements, you have to balance the whole chemical compound.
Thus,
V2O5 + 5 CaS -> 5 CaO + V2S5
LHS CHECK:
V: 2
O: 5
Ca: 5
S: 5
RHS CHECK:
V: 2
O: 5
Ca: 5
S: 5
3) S8 + O2 -> SO2
LHS:
S: 8
O: 2
RHS:
S: 1 x 8 [to balance with LHS]
O: 2
When you balance any elements, you have to balance the whole chemical compound.
S8 + O2 -> 8 SO2
When we add 8 to the RHS, it gives us 8S, 16 O.
In order to balance that into the RHS, I need to multiply the O2 by 8, which will give 8(O2) = 16 O particles.
Therefore, S8 + 8 O2 -> 8 SO2 is the final answer for (3).
What is the Kc for the following reaction at equilibrium at 800∘C if [CO2]= 0.030 M ? CaCO3(s)⇌CaO(s)+CO2(g)
Answer:
0.030
Explanation:
Step 1: Write the balanced reaction at equilibrium
CaCO₃(s) ⇌ CaO(s) + CO₂(g)
Step 2: Calculate the concentration equilibrium constant
The concentration equilibrium constant (Kc) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients. It doesn't include solids or pure liquids.
Kc = [CO₂] = 0.030
How many moles are in 454 Liters of a gas?
Answer:
20.27 mol
Explanation:
454 L x (1 mol/22.4 L) = 20.27 mol
Examination of the first few successive ionization energies for a given element usually reveals a large jump between two ionization energies. For example, the successive ionization energies of magnesium show a large jump between IE2 and IE3. The successive ionization energies of aluminum show a large jump between IE3 and IE4. Explain why these jumps occurs and how you might predict them.
Answer:
See Explanation
Explanation:
Ionization energy refers to the energy required to remove an electron from an atom. Metals have lower ionization energy than non metals since ionization energy increases across a period.
One thing that we must have in mind is that it takes much more energy to remove an electron from an inner filled shell than it takes to remove an electron from an outermost incompletely filled shell.
Now let us consider the case of magnesium which has two outermost electrons. Between IE2 and IE3 we have now moved to an inner filled shell(IE3 refers to removal of electrons from the inner second shell) and a lot of energy is required to remove an electron from this inner filled shell, hence the jump.
For aluminium having three outermost electrons, there is a jump between IE3 and IE4 because IE4 deals with electron removal from a second inner filled shell and a lot of energy is involved in the process hence the jump.
Hence a jump occurs each time electrons are removed from an inner filled shell.
why was the introduction of oxygen such a big deal?
Which letter in the rock cycle diagram represents metamorphic rock?
A)
A.
B)
B.
)
D.
D)
E.
Answer:
B.Explanation:
Hopes this helps. Mark as brainlest plz!Answer:
b
Explanation:
learned this in science class
What is the energy of the reactants?
k]
What is the energy of the products?
k]
What is the activation energy of the forward reaction?
k]
What is the activation energy of the reverse reaction?
k]
What the energy of the forward reaction?
k]
What is the energy of the reverse reaction?
Is the forward reaction endothermic or exothermic?
Is the reverse reaction endothermic or exothermic?
Answer:
1. The energy of the reactant is 50 KJ
2. The energy of the product is 100 KJ
3. The activation energy of the forward reaction is 200 KJ.
4. The activation energy of the reverse reaction is 150 KJ.
5. The energy of the forward reaction is +50 KJ
6. The energy of the reverse reaction is –50 KJ
7. Endothermic reaction
8. Exothermic reaction
Explanation:
1. Determination of the energy of reactant.
From the diagram given above, the energy of the reactant is 50 KJ
2. Determination of the energy of product.
From the diagram given above, the energy of the product is 100 KJ.
3. Determination of the activation energy of the forward reaction.
The activation energy is the energy between the reactant and the peak. It can be obtained as follow:
Energy of reactant (Eᵣ) = 50 KJ
Energy at the peak (Eₕ) = 250 KJ
Activation energy (Eₐ) =?
Eₐ = Eₕ – Eᵣ
Eₐ = 250 – 50
Eₐ = 200 KJ
Thus, the activation energy of the forward reaction is 200 KJ
4. Determination of the activation energy of the reverse reaction.
Energy of reactant (Eᵣ) = 100 KJ
Energy at the peak (Eₕ) = 250 KJ
Activation energy (Eₐ) =?
Eₐ = Eₕ – Eᵣ
Eₐ = 250 – 100
Eₐ = 150 KJ
Thus, the activation energy of the reverse reaction is 150 KJ
5. Determination of the energy of the forward reaction.
Energy of reactant (Eᵣ) = 50 KJ
Energy of product (Eₚ) = 100 KJ
Enthalpy change (ΔH) =?
ΔH = Eₚ – Eᵣ
ΔH = 100 – 50
ΔH = +50 KJ
Thus, the energy of the forward reaction is +50 KJ
6. Determination of the energy of the reverse reaction.
Energy of reactant (Eᵣ) = 100 KJ
Energy of product (Eₚ) = 50 KJ
Enthalpy change (ΔH) =?
ΔH = Eₚ – Eᵣ
ΔH = 50 – 100
ΔH = –50 KJ
Thus, the energy of the reverse reaction is –50 KJ
7. The forward reaction is endothermic reaction because the energy of the product is higher than the energy of the reactant which leads to positive energy of the forward reaction (+50 KJ).
8. The reverse reaction is exothermic reaction because the energy of the product is lesser than the energy of the reactant which leads to negative energy of the reverse reaction (–50 KJ). In a nut shell, we can say that the energy of the reverse reaction is exothermic because its energy of reaction is –50 KJ.
What volume (in mL) of 0.3900 M HCl is required to neutralize 50.00 mL of 0.8000 M NaOH?
Answer:
102.6 mL
Explanation:
The reaction that takes place is:
NaOH + HCl → NaCl + H₂OFirst we calculate how many NaOH moles are there in 50.00 mL of a 0.8000 M solution:
0.8000 M * 50.00 mL = 40 mmol NaOHThen we convert NaOH moles into HCl moles:
40 mmol NaOH * [tex]\frac{1mmolHCl}{1mmolNaOH}[/tex] = 40 mmol HClFinally we calculate the volume of a 0.3900 M solution would contain 40 milimoles:
40 mmol / 0.3900 M = 102.6 mLQuestion 9
5 pts
Which energy transfer is correctly matched?
Fusion in the sun: chemical to light and heat
Lighting a match: heat energy into chemical energy
a cell phone: thermal to electrical
Turning on a ceiling fan: electrical to mechanical
Answer:
fusion in the sun
Explanation:
I know this because I am currently talking this test and I know it cause I did it
Answer:Turning on a ceiling fan: electrical to mechanical
I took the test and Fusion in the sun: chemical to light and heat Lighting a match: sound energy into chemical energy were the wrong answers.
How is neutrophilia defined?
Juan observes a material in the rocks of a hilluan hammers off a piece and then examines the pieces with a hana tena He
makes the following notes about what he observes
• has luster
• cubic crystals
• clear in color
What did he most likely observe through the hand lens?
A)
rock
B)
fossil
mineral
D)
animal bones
Answer:
I definitely think he mostly observed that it was clear in color.
Explanation:
Only animals and not plants can adapt to their environment true or false
Answer:
true
Explanation:
np have a good day brainliest?
Dawn is comparing how different animals move and the structures they use to move. She made the table shown below.
Animal Method of movement Structures used for movement
panther walks legs and feet
parrot flies wings
shark swims
Which structure completes the table for the shark?
eyes and brain
skin and scales
tail and fins
teeth and jaws
Answer:
tail and fins
Explatanation:
A(n) _________ is an atom or a group of atoms with either a positive or negative charge
O compound
O ion
O molecule
O nucleus
Answer:
the answer is ion..
hope it helps..
How many liters is 3.3 moles of a gas?
Answer:
224.1
Explanation:
How saliva works as a buffering agent?
Answer:
The carbonic acid/bicarbonate buffer is the major buffer in stimulated saliva, with bicarbonate acting mainly to neutralize acids produced by bacteria when they digest sugars in the mouth or acids from the stomach. The concentration of the bicarbonate ion depends largely on the salivary flow rate.
Explanation:
Basta Yan sagut ko eh
Answer:
The carbonic acid/bicarbonate buffer is the major buffer in stimulated saliva, with bicarbonate acting mainly to neutralize acids produced by bacteria when they digest sugars in the mouth or acids from the stomach. The concentration of the bicarbonate ion depends largely on the salivary flow rate
Explanation:
After a metal object turns to dust (rust), it would have _____.
Need Help please
Answer:
The answer is high entropy.
Explanation:
Which process breaks down a compound into its elements?
Answer:
Chemical decomposition
Explanation:
Chemical decomposition, analysis or breakdown is the separation of a single chemical compound into its two or more elements or to simple compounds.
Answer:
Other processes that break down chemical substances into simpler substances, include depolymerization, decomposition, etc
Hope it helps!!!
Explanation:
What type of consumer eats only producers?
Answer: Primary consumers make up the second trophic level. They are also called herbivores. They eat primary producers—plants or algae—and nothing else. For example, a grasshopper living in the Everglades is a primary consumer
Answer:
primary consumer make up the second trophic level .they are also herbivores they eat primary consumer plants or alger and nothing else .for example a grasshopper living in the everglades is a primary consumer
2. A plant growing in response to the sunlight.
A.Gravitropism
B.Phototropism
C.Thigmotropism
D.Hydrotropism
Answer:
phototropism
Explanation:
since photo is (light?
1. Predict the missing product in the acid-base reaction.
HCL + NaOH
H2O +
HNa
CO2
Nach
О
CLOH
Answer: The missing product in the acid base reaction is NaCl.
Explanation:
Neutralization or acid base reaction is a chemical reaction in which acid and base combine to form salt and water. Acids donate [tex]H^+[/tex] ions and bases donate [tex]OH^-[/tex] ions in water which combine to form water molecules.
The balanced chemical reaction for the given reaction is ;
[tex]HCl+NaOH\rightarrow NaCl+H_2O[/tex]
Thus the missing product is NaCl.
The missing product in the acid-base reaction is NaCl.
The balanced chemical reaction for the given reaction is ;
[tex]HCl +NaOH[/tex] → [tex]NaCl +H_20[/tex]
What is an acid-base reaction?When acid and base react with each other they form salt and water. Water and salt both are neutral which means, whenever acid and base react together, they are neutralized by each other.
Neutralization or acid base reaction is a chemical reaction in which acid and base combine to form salt and water.
Acids donate [tex]H^{+}[/tex] ions and bases donate [tex]0H^{-}[/tex] ions in water which combine to form water molecules.
Since acid and base neutralize each other's effect,it is called neutralization reaction.
For Example: When Sodium Hydroxide ( NaOH) , a base, reacts with Hydrochloric acid (HCl) , it forms the salt, Sodium Chloride (NaCl) and Water.
The balanced chemical reaction for the given reaction is ;
[tex]HCl +NaOH[/tex] → [tex]NaCl +H_20[/tex]
Thus the missing product in the acid-base reaction is NaCl.
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Calculate the frequency of a light wave that has a wavelength of 9.2dm.
When Thomas Edison first sold electricity, he used zinc coulometers to measure charge consumption. (In a coulometer the cathode is weighed before a current is passed through it, and then again after the passage of current. The weight increase is proportional to the amount of current that flows through the cathode.) If the zinc plate in one of Edison's coulometers increased in mass by 14.47 g, how much charge had passed through it
Answer:
The answer is "[tex]42537.93 \ C[/tex]".
Explanation:
Molar mass : [tex]Z_n = 65.38 \ \frac{g}{mol}\\\\[/tex]
[tex]\to Zn^{2+} + 2e^{-} = Zn\\\\[/tex]
[tex]\therefore\\\\ \to 65.38 \ g \ of\ Z_n \ require: \\\\ \to 2 \times 96500\ C\\\\\to 14.41 \ g\ require,\\\\ \to \frac{(14.41 \times 2 \times 96500)}{65.38} \ \frac{g}{mol} = 42537.93 \ C[/tex]