10 divided by 2 im confused
if your serious about this question then it is 5
Which observation is the best indication that a chemical reaction has occurred?
A. Change in temperature
B. Presence of ashes
C. Change from liquid to gas
D. Absence of fizzing
Answer:
B: Presence of ashes
Explanation:
Burning molecules turns them into other molecules
Answer:B
Explanation:
When vinegar and baking soda react, the mixture becomes cold to the touch and a gas and a new liquid substance are formed. Which best describes what is occurring in the reaction? The reaction is chemical and endothermic. The reaction is chemical and exothermic. The reaction is non-chemical and endothermic. The reaction is non-chemical and exothermic.
Answer:
A
Explanation:
The mentioned reaction between vinegar and baking soda is a type of chemical reaction and endothermic reaction as the reaction proceeds with absorption of energy which turns the mixture cold.
What is endothermic reaction?An endothermic reaction is defined as a chemical reaction which is a thermodynamic process accompanied by an increase in enthalpy of the system.In this process, a system absorbs energy from the surroundings which is mainly thermal energy.
Thus an endothermic reaction leads to an increase in the temperature of the system with a decrease in the temperature of the surroundings.Endothermic reactions usually involve the formation of bonds which requires input of energy.In endothermic reactions, entropy of the surrounding decreases.
Many endothermic processes involve the physical changes rather the chemical changes.In an endothermic reaction ,the potential energy of products is greater than that of reactants.
Learn more about endothermic reaction,here:
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Eliza places an 18-gram piece of an unknown substance into a graduated cylinder that is filled with 5 mL of water, and the water rises from the 5 mL line to the 8 mL. What is the density of the unknown substance in g/mL?
Answer:
6g/mL
Explanation:
Given parameters;
Mass of the unknown substance = 18g
Volume of water before the mass is introduced = 5mL
Volume of water after the mass is introduced = 8mL
Unknown:
Density of the mass = ?
Solution:
Density is the mass per unit volume of a substance.
Density = [tex]\frac{mass}{volume}[/tex]
Mass is the amount of matter in a substance
Volume is the space occupied by a body
Volume of the body = 8mL - 5mL = 3mL
Insert the parameters and solve;
Density = [tex]\frac{18g}{3mL}[/tex] = 6g/mL
Answer:
I think its 6g or 16g but im pretty sure its 6g
Explanation:
someone help me please i’ll give brainly
[tex]\huge\boxed{Sublimation}[/tex]
_____________________________________Sublimation:Sublimation is a process in which the solid molecules gain energy from their surrounding and they now have enough energy to overcome the force of attraction with the neighboring molecules, thus they escape into the surrounding without going through the liquid phase, that means they directly jump to the vapor phase.
_____________________________________EndothermicThose process which absorb energy from their surrounding to form the product are called endothermic process. Since the SUBLIMATION requires additional energy, it is an endothermic change.
_____________________________________Best Regards,'Borz'12 Ethene gas, CH is completely burned in excess oxygen to form carbon dioxide and water
The equation for this exothermic reaction is shown.
CH 30, - 200, 2H,0
The table shows the bond energies involved in the reaction
bond
bond energy
(kJ/moly
614
413
C-C
CHH
0 0
СО
495
799
O-H
467
What is the total energy change in this reaction?
A-954 kJ/mol
B-1010 kJ/mol
C-1313 kJ/mol
D-1359 kJ/mol
Answer:
12 Ethene gas, CH is completely burned in excess oxygen to form carbon dioxide and water
The equation for this exothermic reaction is shown.
CH 30, - 200, 2H,0
The table shows the bond energies involved in the reaction
bond
bond energy
(kJ/moly
614
413
C-C
CHH
0 0
СО
495
799
O-H
467
What is the total energy change in this reaction?
A-954 kJ/mol
B-1010 kJ/mol
C-1313 kJ/mol
D-1359 kJ/mol
Explanation:
thats all you said
The specific heat capacity of a certain type of cooking oil is 1.75 J/(g⋅∘C). What is the amount of heat exchanged when the temperature of 2.76 kg of this oil is cooled from 191∘C to 23 ∘C?
Answer:
Q = -811440 J
Explanation:
Given data:
Mass of oil = 2.76 Kg (2.76× 1000 = 2760 g)
Initial temperature = 191 °C
Final temperature = 23°C
Specific heat capacity of oil = 1.75 J/g.°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 23°C - 191 °C
ΔT = -168°C
Q = 2760 g ×1.75 J/g.°C ×-168°C
Q = -811440 J
Negative sign show heat is released.
Design criteria are the desired features of a design. Identify at least two criteria for the design of the ammonia-making process. Explain why these criteria are important.
Answer:
The ammonia production design process has two design requirements;
Sustainable renewable energy production of hydrogen. Sustainable use of another thermal ammonia-water process to retrieve ammonia throughout the wastewater.Explanation:
In the following process, ammonia is provided by natural gas:
[tex]H_2 + RSH \to RH + H_2S\\\\H_2S + ZnO \to ZnS + H_2O \ \ (Waste \ water)\\\\CH_4 + H_2O \to CO + 3H_2\\\\CO + H_2O \to CO_2 + H_2\\\\[/tex]
Ammonia would then be generated in a process called also as Haber-Bosch process by responding to produced hydrogen to nitrogen throughout the presence of catalysts.
[tex]3H_2 + N_2 \to 2NH_3[/tex]
Answer:
Sustainable renewable energy production of hydrogen.
Sustainable use of another thermal ammonia-water process to retrieve ammonia throughout the wastewater.
Explanation:
PLEASE ANSWER ASAP
*Will mark *25 points
Question 5 of 5
The Monroe Doctrine changed the United States' role in the world by:
O A. allowing the country to control a huge number of colonies around
the world.
O B. increasing the country's power to influence political decisions in
Europe.
C. giving the country a larger role in protecting other countries in the
Americas.
D. forcing the country to use its military to support all democratic
revolutions.
Answer:It is C i got it correct
Explanation:
Answer:
C. giving the country a larger role in protecting other countries in the
Americas.
Explanation:
Please help me It would mean everything!!
1. high
You are correct.
Cold region have more air pressure because air is denser.
Gamma rays are often used to kill microorganisms in food, in an attempt to make the food safer. Some people contend that this irradiated
food is actually less safe to eat. Which, if true, would most effectively dispute their idea? (1 point)
a
Irradiated food only emits alpha particles, which are harmless.
Ob
Irradiated food is shown to not be radioactive.
C
Irradiated food only contributes to background radiation.
Irradiated food has molecules that undergo transmutation,
Od
Answer:
b . Irradiated food is shown to not be radioactive.
Explanation:
If it can be proven that irradiated food is not radioactive, then it will effective dispute the idea that irradiated food are less safe to eat.
An irradiated food is one in which ionizing radiations have been employed to improve food quality. Thus, bacteria and other food spoilers can be exterminated from the food. Most irradiated food do not contain radiation and are fit for consumption.If it can be proven, that this is true, then it will challenge the idea that irradiated foods are not safe.
What is the smallest unit of cellular organization?
Answer:
A cell
Explanation:
Potato strips placed in a container of concentrated salt water will ultimately __.
Thanksgiving is November 26th. Today is November 9th. How many seconds are there until Thanksgiving Day?
Which of the following diagrams correctly represents the formation of a compound consisting of magnesium and fluorine?
Answer:
See explanation
Explanation:
The image attached describes the formation of magnesium fluoride.
Magnesium has two valence electrons while fluorine has seven valence electrons. Magnesium can now transfer one electron each to two fluorine atoms thereby forming the compound MgF2.
This has been shown pictorially in the image attached to this answer.
How to do this question plz answer me
Answer:
dissolved
Explanation:
The figure shows sodium chloride is in solution. It gets that way by being dissolved.
If 9.6 X 1021 molecules of hydrogen are reacted with excess nitrogen, how many liters of ammonia can be produced at STP?
The volume of NH₃ produced at STP : 0.237 L
Further explanationReaction
N₂ + 3H₂ → 2NH₃
1 mol = 6.02 x 10²³ particles
9.6 X 10²¹ molecules of Hydrogen, mol :
[tex]\tt \dfrac{9.61\times 10^{21}}{6.02\times 10^{23}}=1.596\times 10^{-2}~moles[/tex]
mol H₂ : mol NH₃ = 3 : 2
mol NH₃ :
[tex]\tt \dfrac{2}{3}\times 1.596\times 10^{-2}=0.0106[/tex]
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.
The volume of NH₃ :
[tex]\tt 0.0106\times 22.4=0.237~L[/tex]
The density of lead is 11.4g/cm3. What volume, in ft3, would be occupied by 10.0 g of lead?
Answer:
The volume is 3.09 ft^3.
Explanation:
The formula for volume is mass divided by density. 10.0 g / 11.4 g/cm^3 = 0.87719. Converted to cubis foot is 3.09 ft^3. I hope this helps you.
List and define the 3 parts of a chemical equation (R->P).
Answer:
R- reactants
arrow- yields
p- products
Explanation:
Which has kinetic energy?
Ob
a tank of gasoline
a moving car
a battery
Ос
Od
water in a reservoir
Answer:
a moving car
Explanation:
because The faster an object is moving, the more kinetic energy it has. Any object that is moving has kinetic energy – the moving object has energy because of its motion.
An atom of a certain element has 12 protons, 14 neutrons, and 2 valence electrons. What is the name of this element?
Given :
An atom of a certain element has 12 protons, 14 neutrons, and 2 valence electrons.
To Find :
The name of this element.
Solution :
We know, element with atomic number ( number of protons ) 12 and valance electrons is Magnesium.
Now, isotope of magnesium of proton with 14 neutrons is Mg-16 .
Therefore, name of element is Mg-16 .
Hence, this is the required solution.
paragraph on water cycle
Answer:
The water cycle or hydrologic is a continuous cycle where water evaporates, travels into the air and becomes part of a cloud, falls down to earth as precipitation, and then evaporates again. ... These areas are usually close to oceans or large bodies of water that allow more water to evaporate and form clouds.
Explanation:
3. Gold-198 decays with a half-life of 2.7 days according to the equation:198Au → 0−1β + 198Cd
a. Find the value of the rate constant, k. Include units.
b. How much of a 10.0 g sample of Au-198 remains after seven days? (Use the integrated rate law formula.)
a. k=0.256/day
b.sample of Au-198 remains after seven days : 1.67 g
Further explanation1. A half-life of 2.7 days⇒t1/2=2.7 days
The half-life can be expressed in a decay constant( λ)
[tex]\tt \displaystyle t_ {1/2} = {\dfrac {\ln (2)} {\lambda}}\\\\\lambda(or~k)=\dfrac{0.693}{2.7}=0.256/day[/tex]
2. We can use formula : (integrated rate law) :
[tex]\tt ln[A]=-kt+ln[Ao]\\\\ln(\dfrac{Ao}{A})=kt[/tex]
Ao=10 g
t=7 days
k=0.256/day
[tex]\tt ln(\dfrac{10}{A})=0.256\times 7\\\\ln(\dfrac{10}{A})=1.792\\\\e^{1.792}=\dfrac{10}{A}\\\\6=\dfrac{10}{A}\rightarrow A=1.67~g[/tex]
The mass of Au-198 that remains after seven days is 1.62 g.
We know that radioactive decay is a first order reaction hence;
k = 0.693/ t12
Where;
k = rate constant
t12 = half life
k = 0.693/ 2.7 days = 0.26 day-1
Using;
N =Noe^-kt
No = amount of radioactive material initially present
N = mass of radioactive substance present at time t
N = 10 e^-(0.26 × 7)
N = 1.62 g
The mass of Au-198 that remains after seven days is 1.62 g.
Learn more about radioactive decay: https://brainly.com/question/14077220
I WILL GIVE BRANLIEST HELP HELP HELP THE SUBJECT IS ACTUALLY SCIENCE What factor is a mushroom in an ecosystem? Abiotic or Biotic?
Answer: The answer is biotic
Explanation:Mushrooms are biotic because they are living things. Abiotic means non living, so these are factors in the environment that influence a living thing's life and chance of survival
Answer: jdusjzj bacteria germs
Explanation:
what’s the answer please gelp
Answer:
Option A. 1.8×10²⁴ molecules.
Explanation:
Data obtained from the question include:
Number of mole of methane = 3 moles
Number of molecules of methane =?
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ molecules.
Thus, 1 mole of methane equally contains 6.02×10²³ molecules.
With the above information in mind, we can obtain the number of molecules in 3 moles of methane as follow:
1 mole of methane contains 6.02×10²³ molecules.
Therefore, 3 moles of methane will contain = 3 × 6.02×10²³ = 1.8×10²⁴ molecules.
Thus, 3 moles of methane contains 1.8×10²⁴ molecules.
What are the coefficients for the following chemical reaction?
___Be(BrO3)2 --> ___BeBr2+___O2
A.
1, 1, 3
B.
2, 2, 6
C.
2, 2, 3
D.
2, 1, 2
1 points
QUESTION 12
The previous question is an example of what type of chemical equation?
A.
Synthesis
B.
Decomposition
C.
Single Re-Placement
D.
Double Re-Placement
Explanation:
A and D. the answer is a and d
Which of the following is the best hypothesis?
O A. Why does salt water boil at a higher temperature than
pure water?
O B. Americans use too much salt when they cook.
O C. If I add salt to water, it will cause the boiling point to increase.
D. It's better to cook pasta in salt water than in pure water.
The work done by effort is called
Answer:
load
Explanation:
the load is the work done by the effort on the machine
The insect population competes for _______________________ and nectar.
Answer:
eachother or different type of flower
Explanation:
Use the drop-down menus to select the sentences that show precise use of pronouns.
1. Fred visited Nick after his graduation.
2. After Nick's graduation, Fred visited him.
1. Marie told Sarah that she makes great spaghetti.
2. Marie told Sarah, "You make great spaghetti."
1. John broke the fence with his bike.
2. John's bike hit a fence and it broke.
Answers
Sentence 1
Sentence2
Answer:
sentence 2, sentence 2, sentence 1
Explanation:
it was right for me on edge 2020
Answer:
1. Fred visited Nick after his graduation.
2. After Nick's graduation, Fred visited him.
1. Marie told Sarah that she makes great spaghetti.
2. Marie told Sarah, "You make great spaghetti."
1. John broke the fence with his bike.
2. John's bike hit a fence and it broke.