Answer:
The law of conservation of mass states that in a closed system, mass is neither created nor destroyed during a chemical or physical reaction. The law of conservation of mass is applied whenever you balance a chemical equation.
Explanation:
According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
The law of conservation of mass is useful for a number of calculations and can be used to solve for unknown masses, such the amount of gas consumed or produced during a reaction.
It is applicable in a chemical when the the mass of the products in a chemical reaction is equal to the mass of the reactants.
But it is not applicable in a nuclear fusion as some of the mass is generated as energy.
Which of the following can be used as lubricant
Answer:
Explanation:
B is the ans
pls mark BRAINLIEST
1. A block of plastic occupies a volume of 25.0 mL and weighs 20.5 g. What is its density? Circle or highlight
the correct answer. (5 pts)
a. 512 g/mL
c. 0.37 g/mL
b. 1.62 g/mL
d. 0.82 g/mL
Savvas Realize. Investigation 8 Experiment 1
Answer:
–1065.25 KJ of energy.
Explanation:
From the question given above, the following data were obtained:
4FeO + O₂ —> 2Fe₂O₃ ΔH = –560.66 kJ
From the balanced equation above,
The formation of 2 moles of Fe₂O₃ released –560.66 kJ of energy.
Finally, we shall determine the amount of heat energy released when 3.8 moles of Fe₂O₃ are produced. This can be obtained as follow:
From the balanced equation above,
The formation of 2 moles of Fe₂O₃ released –560.66 kJ of energy.
Therefore, the formation of 3.8 moles of Fe₂O₃ will release
= (3.8 × –560.66)/2 = –1065.25 KJ of energy.
Thus, –1065.25 KJ of energy is released from the reaction.
Which of the following processes occurs with a decreaseentropy of the system
Explanation: Entropy decreases when the number of moles of gas decreases during a reaction. In the case of the correct answer, the number of moles of gas decreases from two to one. When a substance goes from a solid to a gas (sublimation) or from a liquid to a gas (evaporation), entropy increases.
Fill in the blank,
The law of conservation of mass
says substances can neither be
nor
Answer:
created or destroyed
Explanation:
The law of conservation of mass tells us that during a chemical reaction, matter is neither created or destroyed; it can change from one form to another but there will be no gain or loss of mass.
PLEASE HELP WITH CHEM !! Calculate the [OH-] of each of the following solutions given the [H+]. AND Classify each of the solutions in the question above as either acid, base, or neutral. AND FIND THE PH
pH, pOH, [H+], and [OH-] are all interrelated. For simplicity, we assume that we're working with aqueous solutions at 25 °C.
The following mathematical relations are relevant here:
pH = -log[H⁺]pOH = -log[OH⁻][H⁺] = 10^-pH[OH⁻] = 10^-pOHpH + pOH = 14[H⁺] × [OH⁻] = 10^-14A pH of 7 is neutral; a pH less than 7 is acidic; and a pH greater than 7 is basic.
---
We are given four solutions of varying [H⁺], and we want to find the pH and the [OH⁻]. The pH will tell us whether the solution is neutral, an acid, or a base.
Finding the [OH⁻]Using the relationship [H⁺] × [OH⁻] = 10^-14, we can calculate the [OH⁻] of each solution by dividing 10^-14 by the given [H⁺]:
[OH⁻] = 10^-14/(3.3 × 10^-5) = 3.0 × 10^-10
[OH⁻] = 10^-14/(4.0 × 10^-8) = 2.5 × 10^-7
[OH⁻] = 10^-14/(7.2 × 10^-11) = 1.4 × 10^-4
[OH⁻] = 10^-14/(8.2 × 10^-4) = 1.2 × 10^-11
Note: While not indicated here, the units for [H⁺] and [OH⁻] are moles/liter (M).
Finding the pHTo find the pH of each solution, we take the negative logarithm of the [H⁺] with base 10, i.e., pH = -log₁₀[H⁺]:
pH = -log(3.3 × 10^-5) = 4.48
pH = -log(4.0 × 10^-8) = 7.40
pH = -log(7.2 × 10^-11) = 10.14
pH = -log(8.2 × 10^-4) = 3.09
Note that, for significant figures involving logarithms, the number of decimal places should equal the number of significant figures in the argument of our logarithm (the argument is what we're taking the -log of). Since we're taking the -log of quantities given to two significant figures, our corresponding pH values are given to two decimal places.
Acid, Base, or Neutral?As mentioned above, a pH = 7 is neutral, a pH < 7 is acidic, and a pH > 7 is basic.
4.48 < 7, so the first solution is an acid.
7.40 > 7, so the second solution is a base.
10.14 > 7, so the third solution is a base.
3.09 < 7, so the fourth solution is an acid.
Which shows substances placed in order from strongest to weakest attractive forces at room temperature?
es )
A)
1. Br (s) 2. Br (9) 3 Br (1)
B)
1. Br (s) 2. Br (1) 3 Br (9)
1. Br (9) 2. Br (1) 3 Br (s)
D)
1. Br (aq) 2. Br (1) 3 Br (9)
Dhusical Dror
Explanation:
es la b es ciertos que es el resultado
Which statement is correct?
A. Physical changes produce new substances; chemical changes do not.
B. Chemical changes produce new substances; physical changes do not.
C. Both physical changes and chemical changes produce new substances.
D. Neither physical changes nor chemical changes produce new substances.
Answer:
B. Chemical changes produce new substances; physical changes do not.
Explanation:
Physical changes only alter appearances, while chemical changes are interactions that create new chemical formulas.
2. How many moles are in 2.8 Liters of CO2 gas?
Answer:
0.125 moles
Explanation:
2.8 litres is equivalent to 2.8dm³
At STP,
1 mole = 22.4 dm³
x mole = 2.8 dm³
Cross multiply
22.4x = 2.8
Divide both sides by 22.4
x = 2.8/22.4
x = 0.125
Does anybody know how to do this if so please help !
Answer:
add x to 7 and divide by 3
Explanation:
easier formula
helllp meee pls . ....... ..... . . . . .
. . . . . . . . . .. . . . . ... .. . . . . ....... . . .. . . .. . . . . . . . . ... .. . . . ....
Which region on the map has the highest risk of future landslides? a- Region 1 b-Region 2 c- Region 3 d- there is no way to make comparisons about the risk of future landslides? The subject is science (8th grade)
Answer:
Explanation:
Which region on the map has the lowest risk of future landslides?
How does the environment in which an organism lives determine which traits are adaptations?
can someone plss help me??
Answer:
When an organism lives in a certain environment there is a process called natural selection. Natural selection ensures that the organisms of a species with the best traits suited for an environment will reproduce and pass on those traits to the offspring.
Explanation:
The theory of natural selection was studied by Charles Darwin in The Origin of Species by Means of Natural Selection if you need more information.
A drug company is testing the effects of a new drug designed to prevent hair loss. Of the 2,000 people in the trial, 1,700 people receive the drug and the other 30 people receive a sugar pill. What is the purpose of the group receiving the sugar pill? A. The group is being used as the control group B. The group is being used as the dependent variable C. The group is being used as the independent variable D. The group is being used as the manipulated variable
Answer:
A
Explanation:
The correct answer would be that the group being given the sugar pill is being used as the control group.
In a typical experimental study, there are two groups of subjects:
1. The treatment or the experimental group
2. The control group
The treatment group receives the treatment variable while the control group does not receive or is given a placebo. Thus, the control group act as the reference group for comparison basis. Any difference in the observation between the two groups would be attributed to the treatment variable.
The correct option is, therefore, A.
WILL MARK BRAINLIEST FOR CORRECT ANSWER
Continue reading from Ruby Bridges’s autobiography.
We drove down North Galvez Street to the point where it crosses Alvar. I remember looking out of the car as we pulled up to the Frantz school. There were barricades and people shouting and policemen everywhere. I thought maybe it was Mardi Gras, the carnival that takes place in New Orleans every year. Mardi Gras was always noisy.
As we walked through the crowd, I didn’t see any faces. I guess that’s because I wasn’t very tall and I was surrounded by the marshals. People yelled and threw things. I could see the school building, and it looked bigger and nicer than my old school. When we climbed the high steps to the front door, there were policemen in uniforms at the top. The policemen at the door and the crowd behind us made me think this was an important place.
It must be college, I thought to myself.
–Through My Eyes,
Ruby Bridges
What evidence in the text supports the idea that Bridges did not realize the significance of her first day? Check all that apply.
“I remember looking out of the car as we pulled up to the Frantz school.”
“I thought maybe it was Mardi Gras.”
“As we walked through the crowd, I didn’t see any faces.”
“[The school] looked bigger and nicer than my old school.”
“The crowd behind us made me think this was an important place.”
“It must be college, I thought to myself.”
Answer: I remember looking out of the car as we pulled up to the Frantz school.”
“I thought maybe it was Mardi Gras.”
“As we walked through the crowd, I didn’t see any faces.”
“[The school] looked bigger and nicer than my old school.”
“The crowd behind us made me think this was an important place.”
“It must be college, I thought to myself.
Explanation:
“I thought maybe it was Mardi Gras.”
“[The school] looked bigger and nicer than my old school.”
“It must be college, I thought to myself.”
If 115grams of a substance reacts with 84grams of another substance, what will be the mass of the products after the reaction?
What is the type of structure indicated below?
a- ionic structure
b-resonance structure
c- molecular structure
d-electron dot structure
Answer:
Electron dot structure
Explanation:
This is because electron dot structure is the structure that shows or indicate valence electrons of an atom and dots
is use around the element symbols . The number of dots shows the total number of valence electrons that are present in the atom of the molecules.
Can anyone solve this chemical reaction?
Answer:
1) BaCl2 + Na2O = BaO + 2NaCl
2) C4H8 + 6O2 = 4CO2 + 4H2O
3) MgCO3 + 2K = K2CO3 + Mg
4) N2 + 3F2 = 2NF3
What element is found in water?
1. Carbohydrate
2. Carbon
3. oxygen
Explanation:
3. the element is oxygen
Pls help me with this problem
Answer:
2 and 5 would be my answers
Explanation:
describe each of the three states of matter (solid, liquid, gas)
Explanation:
In a solid particles are firmly together and are stuck in a regular pattern
in a liquid particles still touch but arent in a fixed pattern
in a gas particles move quickly in all directions
balanced the equation please Fe + O2 → Fe2O3
Answer: The balanced equation is 4,3,2,
Answer: Balanced equation = 4Fe + 3O2 => 2Fe2O3.
Explanation:
1. If a 250 kg rock is sitting on the ledge of Ls cliff 295 meters high, then what is the
potential energy of the rock?
Answer:
Explanation:
P.E=M*G*H
P.E=250*10*295
P.E=737,500J
What are the two major causes of genetic disorders in humans?
Answer:
genetic mutation or the environmental exposures
What is the pH of an aqueous solution of HCl with a hydrogen ion
concentration of [H+] = 6.7 x 10-6 M? Round your answer to the nearest
hundredth.
Answer:
pH = 5.17
Explanation:
pH = -log[H+] = -log(6.7 x 10^-6) = 5.17
1. Cancer is a disease in which cells
a. grow and divide uncontrollably. b. die before they can mature.
c. stop producing DNA. d. die during mitosis.
____ 2. Which of these traits is controlled by a gene with multiple alleles?
a. straight hairline b. smile dimples
c. widow’s peak d. blood type
____ 3. Which of these is an example of the benefits of genetic engineering?
a. cross-breeding to create disease-resistant crops
b. creating human insulin to treat people with diabetes
c. analyzing karyotypes and pedigree charts
d. growing a new plant from a cutting
____ 4. A carrier is a person who has
a. one recessive and one dominant allele for a trait.
b. two recessive alleles for a trait.
c. two dominant alleles for a trait.
d. more than two alleles for a trait.
____ 5. Sex-linked genes are genes on
a. the X chromosome only. b. the Y chromosome only.
c. the X and Y chromosomes. d. all 23 pairs of chromosomes.
______ 6. What is the chromosome theory of inheritance?
a. Chromosomes are carried from parents to offspring on hybrids.
b. Genes are carried from parents to offspring on chromosomes.
c. Hybrid pairs of chromosomes combine to form offspring.
d. Codominant genes combine to form new hybrids.
____ 7. How can a mutation affecting skin be harmful to an animal?
a. It can make the animal more visible to its prey or predators.
b. It can cause disease in the animal.
c. It can make the animal resistant to certain diseases.
d. It can make the animal resistant to drugs
______ 8. What happens during meiosis?
a. Two sex cells combine.
b. Chromosome pairs separate and are distributed into new sex cells.
c. Each sex cell copies itself to form four new chromosomes.
d. Chromosome pairs remain together when new sex cells are formed.
Answer:
1. a
2. a.
3. b.
4. a.
5. c.
6. b.
7. a.
8. c.
Explanation:
give me a example of physical
pls
Answer:
An example of physical is plant life growing in the ground. An example of physical is someone confined to a wheelchair because of disabilities. Of, or produced by the forces of physics.
Explanation:
Diamond is extremely hard and does not conduct electricity.
Which statement explains these properties?.
Answer:
C. It has no delocalised electrons and each carbon atom forms four covalent bonds with other carbon atoms.
Explanation:
Diamond is composed solely by carbon atoms. As the difference of electronegativity between atoms is 0, diamond is a fully covalent compound.The lack of electrical conductivity stems from a lack of available electrons, this means that there are no delocalised electrons.The information in the first point discards options A and D, while the second point discards option B. Thus the answer is option C.
What happens to the limiting reactant during the course of the chemical reaction?
Answer: The limiting reactant is the reactant that gets consumed first in a chemical reaction and therefore limits how much product can be formed.
Explanation:
^
Your opinion on chocolate
What is your opinion on chocolate, any kind like white chocolate dark, etc. also what do you think is the bad side of chocolate?
Answer:
Milk Chocolate
Explanation:
Some chocolates contain lots of sugar, but for Dark chocolate its healthy
Answer:
Milk chocolate the bad side of chocolate is getting fat
Explanation:
have u ever tried shreks snickers before?