A student titrated 50 cm of sulphuric acid (H2SO4)of an unknown concentration
in a flask with sodium hydroxide (NaOH).
The acid required 30 cm3 of 0.500 mol/dm3 NaOH to reach the end point
H2SO4(aq)
+ 2NaOH(aq)
Na2SO4(aq) + 2H2O()
Calculate the concentration the acid.
Concentration =
mol/dm3
Which pieces of equipment are
needed to calculate the velocity of a
falling object?
A stopwatch and balance
B speedometer and magnet
C compass and tape measure
D tape measure and stopwatch
How many grams is 2.393 x 10^24 atoms of CI
70.45 g CI
140.9 ga
140.9 mole CI
70.45 mole CI
How many grams is 2.393 x 10^24 atoms of O
70.45 g O
140.9 g O
63.58 mole O
63.58 g O
Answer: 1. 140.9 g Cl
2. 63.58 g O
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given atoms}}{\text {avogadro's number}}[/tex]
1. [tex]\text{Number of moles of Cl}==\frac{2.393\times 10^{24}}{6.023\times 10^{23}}=3.973moles[/tex]
1 mol of Cl weighs = 35.5 g
Thus 3.973 mol of Cl weighs = [tex]\frac{35.5}{1}\times 3.973=140.9g[/tex]
2. [tex]\text{Number of moles of O}==\frac{2.393\times 10^{24}}{6.023\times 10^{23}}=3.973moles[/tex]
1 mol of O weighs = 16 g
Thus 3.973 mol of O weighs = [tex]\frac{16}{1}\times 3.973=63.58g[/tex]
Which phrase best describes an individual organ
Answer:
the answer is B
Explanation:
Jose was driving to New York City. He traveled 100 miles in the first hour of the trip and 20 miles in the last hour of his trip. Which can we
say about Jose's drive? (speed = distance = time)
A. Jose drove less than 120 miles.
B. Jose drove faster the first hour of his drive.
C. Jose drove slower the first hour of his drive.
D. Jose drove the same speed for the entire drive.
Answer:
b
Explanation:
he drove 5x faster than the time was when he was on the last hour (maybe caught in traffic or wasn't in a rush)
Which best describes the products of a
chemical equation?
A. Chemicals before the reaction starts
B. Chemicals after the reaction ends
C. Chemicals on the left of the arrow
D. Chemicals on the right of the arrow
Answer:
b?
Explanation:
Chemicals after the reaction ends during chemical equation. Therefore, the correct option is option B among all the given options.
What is chemical equation?In chemistry, you will frequently come across a chemical equation. It is a textual depiction of the procedure that takes place throughout a chemical reaction using numbers and symbols.
The reactants are placed on the left side of such an arrow in a chemical equation, while the reaction's products are placed on the right. Though certain equations may imply equilibrium with the reaction occurring in both directions simultaneously, the tip of the arrow normally heads toward the right or product side of the equation. Chemicals after the reaction ends during chemical equation.
Therefore, the correct option is option B.
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I need help with my science project someone help me answer it!
Answer:
food
Explanation:
Lab: Limiting Reactant and Percent Yield
Student Guide
Pre-Lab Information
Purpose Explore the yield of a chemical reaction by identifying the limiting reactant, comparing the
theoretical and actual yields, and explaining the sources of error.
Time Approximately 45 minutes
Question While observing a chemical reaction, how can you tell which reactant is limiting?
Reaction The reaction of copper(II) chloride and aluminum is shown in this balanced equation:
3CuCl2 + 2Al 2AlCl3 + 3Cu
Hypothesis If a substance is the limiting reactant, then it will be fully consumed by the time the
reaction completes because it is the reactant that reacts completely and the reaction
cannot proceed further.
Summary You will react copper(II) chloride with different quantities of aluminum in two trials. You
will also calculate percent yield for Trial 2.
Answer:
pre lab information would be the thing you to ressearch the lab to get the information
Limiting Reactant and Percent Yield Lab Report attached
HELP PLEASE ASAP!!!!!
the cell is undergoing a step of meiosis I. what step is the cell in?
a. the beginning of prophase I
b. the middle of metaphase I
c. the end of anaphase I
d. the middle of telophase I
Answer:
I think it's c
Explanation:
jenensnsjsjs
Help asp please thanks
Balance the following chemical equation:
C2H60+02 → CO2 + H20
Answer:
Explain: In order to balance the chemical equation, you need to make sure the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side. In order make both sides equal, you will need to multiply the number of atoms in each element until both sides are equal.
Please help!
Explain how the Gray Wolf is a keystone species in the Yellowstone
National Park ecosystem.
Wolves are a censerious(critical) keystone species in a healthy ecosystem. By regulating prey populations, wolves authorize(enable) many other species of plants and animals to flourish. Without predators, such as wolves, the system fails to support a natural level of biodiversity.
An organism whose cell contains a nucleus.
Answer:
Eukaryotes
Explanation:
The plant chemical which absorbs sunlight and helps make cell food is
A.osmosis
B.cellulose
C.vaculoe
D.chlorophyll
Answer:
chlorophyll
Explanation:
What happens when you mix calcium chloride and hydrogen peroxide?
Answer:
Explanation: When chlorine reacts with hydrogen peroxide, hydrogen peroxide falls apart into water and oxygen. Chlorine gas hydrolyses into hypochlorous acid (, which subsequently into hypochlorite ions . The reaction between hydrogen peroxide and hypochlorite takes place very quickly.
Are the following equations balanced or unbalanced?
1. SnO2 + 2H2 → Sn + 2 H2O
2. 4NH3 + 5O2 → 4NO + 6H2O
3. 2B2Br6 + 5HNO3 2 B(NO3)3 + HBr
4. 2KNO3 + 1H2CO3 → 1K2CO3 + 2HNO3
A gas has a volume of 15.0 ml at 25 degree Celsius. What is the volume of the gas at 50 degree Celsius.
Answer:
30.0ml
Explanation:
Half of fifty is 25 and 25 represents 15.0ml so 15.0ml×2=30.0ml there for 25+25 is 50
3. An unknown solution has a pH of 10. Based on the pH scale, the solution can be described as
Explanation:
For example, pH 10 is ten times more alkaline than pH 9 and 100 times (10 times 10) more alkaline than pH 8. Pure water is neutral. But when chemicals are mixed with water, the mixture can become either acidic or basic.
An object has balanced forces acting on it. Which of the following describes the result these balanced forces have on the object? A. It remains at rest or speeds up in the same direction. B. It speeds up in the same direction or moves at constant speed. C. It speeds up in the same direction or slows down. D. It remains at rest or moves at constant speed in the same direction.
Answer:
C.It remains at rest or moves at constant speed in the same direction.
Explanation:
First, remember the Newton's 1st law of motion which states that the object at rest will remain at rest and that in motion will stay in motion with the same speed and same direction unless acted by unbalance forces.
Balanced forces on an object occur when two forces at act on an object are equal in size and act in opposite direction. In this case, a stationary object will stay at rest while an object moving will continue to move at the same speed and same direction.
An object acted by balanced forces is said to be at equilibrium, thus the state of motion will be maintained.The object will not accelerate. A good example of an object acted by balanced forces is an object at rest or in constant motion such as a car that stopped at red-light signal or a car travelling at a constant speed.
The boiling process is considered to be____
your answer is D. physical change, because a new substance is not formed.
The boiling process is considered to be a physical change as no new substance is formed.
What is a physical change?Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.
Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.
They involve only rearrangement of atoms and are often characterized to be changes which are reversible.
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Sn(IV) and Br
chemical formula
a solution is prepared by dissolving 55g of CaCl2 into 300g of water. if the Kf of water is -1.86 c/m, shat is the freezing point depression of the solution
Answer:
Relation between , molality and temperature is as follows.
T =
It is also known as depression between freezing point where, i is the Van't Hoff factor.
Let us assume that there is 100% dissociation. Hence, the value of i for these given species will be as follows.
i for = 3
i for glucose = 1
i for NaCl = 2
Depression in freezing point will have a negative sign. Therefore, d
depression in freezing point for the given species is as follows.
=
=
=
Therefore, we can conclude that given species are arranged according to their freezing point depression with the least depression first as follows.
Glucose < NaCl <
Explanation:
State two methods to increase the rate of the chemical reaction and explain
for each, in terms of particle behavior, how each method would increase
reaction rate.
METHOD 1:
Explanation:
METHOD 2:
Explanation:
Answer:
METHOD 1: (surface area of a solid reactant) METHOD 2: (concentration or pressure of a reactant)
Explanation:
METHOD 1: (surface area of a solid reactant) Increasing the surface area of a solid reactant exposes more of its particles to attack. This results in an increased chance of collisions between reactant particles, so there are more collisions in any given time and the rate of reaction increases.
METHOD 2: (concentration or pressure of a reactant) Increasing the concentration means that we have more particles in the same volume of solution. This increases the chance of collisions between reactant particles, resulting in more collisions in any given time and a faster reaction. As we increase the pressure of reacting gases, we increase the rate of reaction.
Calculate the ratio of the velocity of molecular oxygen to the velocity of atomic argon at the same temperature.
I asked this before but still need help
No links, I'm not d*mb
Answer:
Oxygen 1.12 X faster
Explanation:
please help im so bad at science
a.bond energy
c. endothermic reaction
d. exothermic reaction
f.exothermic
g.endothermic
The maps show that northern areas should get
Answer:
We might need more information too answer that question...
Explanation:
Try Inserting A picture ️ :)
Which object is smaller than a cell?
Molecule
Organ
Organism
Tissue
Answer:
Molecule
Explanation:
Levels of organization (atom-molecule-cell-tissue-organ-organ-system-organism)
A book is pushed and released and it slides across a table for a short distance. The book quickly comes to a stop. The book originally
has kinetic energy. To what form of energy is the kinetic energy transformed?
A)
The kinetic energy is transformed into heat.
B)
The kinetic energy is transformed into chemical energy.
C)
The kinetic energy is not transformed into any other type of energy.
Eliminate
D)
The kinetic energy is transformed into electrical energy.
Law of Conservation of Energy
(58P2.c) Energy Transformation
D 149628
Regular Cals
Scientific Cals
My
Answer:
A
Explanation:
The book encountered friction which turned some of the energy into heat.
Type the correct answer in the box. Express your answer to two significant figures.
A reaction between 1.7 moles of zinc Ipdide and excess sodium carbonate ylelds 12.6 grams of zinc carbonate. This is the equation for the
reaction:
Na2CO3 + Zniz - 2Nal +
ZnCoz.
What is the percent yield of zinc carbonate?
The percent yield of zinc carbonate is
5.91
1X.
Answer: The percent yield of zinc carbonate is 5.91 %
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} ZnCO_3=\frac{12.6 g}{125.4g/mol}=0.100moles[/tex]
[tex]ZnI_2[/tex] is the limiting reagent as it limits the formation of product and [tex]Na_2CO_3[/tex] is the excess reagent.
[tex]Na_2CO_3+ZnI_2\rightarrow 2NaI+ZnCO_3[/tex]
According to stoichiometry :
1 mole of produce = 1 mole of
Thus 1.7 moles of [tex]ZnI_2[/tex] will produce=[tex]\frac{1}{1}\times 1.7=1.7moles[/tex] of [tex]ZnCO_3[/tex]
Theoretical yield of [tex]ZnCO_3=moles\times {\text {Molar mass}}=1.7moles\times 125.4g/mol=213.2g[/tex]
percentage yield = [tex]\frac{\text {Experimental yield}}{\text {Theoretical yield}}\times 100=\frac{12.6g}{213.2g}\times 100=5.91\%[/tex]
Answer:
the other person was right EXCEPT it says in 2 significant numbers so the answer is 5.9
Explanation:
i hope this helps. have a wonderful day :))
An alpha particle is identical to a:
helium nucleus
hydrogen nucleus
high energy electron
radium nucleus
Answer: helium nucleus