Answer:
A
Explanation:
USATestPrep
Which of the following is used for purification of water?
a) Sodium bicarbonate
b) Alum
c) Copper sulphate
d) Sodium Hydroxide
A. Sodium bicarbonate is a water treatment method used to soften water (removing calcium and magnesium impurities from it) in older water softener systems. The process uses a chemical reaction to convert the calcium hydroxide (or magnesium hydroxide) into calcium carbonate, which isn't water soluble.
B. Alum, also known as potassium aluminum sulfate, can be used to purify water. ... Add 1.4 ounces of alum powder to the contaminated water in the reaction vessel and carefully stir the mixture with the stirring stick for at least five minutes. Sediment will form as the phosphorous in the water binds with the alum powder.
C. If Copper sulphate crystals are added to water it is called 'hydrated copper sulphate solution'.
If it is added to cold water then:-
it is more saturated
but if it is added to warm water then:-
it is unsaturated
and it turns bluish in colour in dissolving in water
D. Sodium hydroxide is used in the treatment of drinking water to raise the pH of the water to a level that minimizes the corrosion. Raising the pH remains one of the most effective methods for reducing lead corrosion and minimizing lead levels in drinking water.
Diazene, N2H2 (also known as diimine), is commonly used as a reagent for organic syntheses. Label each image with the type of
bond in diazene that it shows.
The first image shown at the left hand side is a pi bond. The other two images show sigma bonds.
In chemistry, a bond results from the overlap of atomic orbitals. This overlap may be end to end (sigma bond) or side by side (pi bond). Having said this, it is easier to decide whether the bonds in the image shown are sigma or bi bonds.
If we label the images; 1,2,3 from left to right, we can see that the overlap in image 1 is side by side. The electron density lies above and below the plane of the bond. This is a pi bond. In images 2 and 3, the overlap occurs in an end to end manner. This is a sigma bond.
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how many seconds are there in 15 hours show work
Answer:
54,000 seconds
Explanation:
seconds in 1 hr = 3600
secs in 15 hrs = 3600×15
→ 54000
Predict the decay process and write the nuclear equation of Cf- 255
Answer:
curium
−
243
,
252
/
99
Es,
251
/
98
Cf,
214
/
82
Pb
Explanation: Im not very good with this but here ya go!
How many moles are contained in 127 grams of lead?
Answer:
18.015
Explanation:
grtdggddgdggrsggrgrgd
Answer:
wut??
Explanation:
A cell phone manufacturer recalled some 50 million lithium batteries installed in cell phones because the batteries were at risk of overheating and exploding. The hazardous waste characteristic of the batteries in this example is __________.
Answer:
universal waste
hope it helps
Explain in your own words:
i. Sublimation
ii. Condensation
iii. Melting
8. Which property is used to determine the degree of polarity between two bonded atoms? A) density B) electronegativity C) pressure D) temperature
Answer:
I think B) electronegativity is the correct answer.
Electronegativity is the property which is used to determine the degree of polarity between two bonded atoms. Therefore, the correct option is option B.
What is polarity?Polarity is the dispersion of electrical charge over the atoms linked by a chemical bond. Bonds between identical atoms, such as H2, are electrically homogeneous in the sense that both hydrogen atoms are electrically neutral, but bonds between different atoms are electrically inequivalent.
Electronegativity is the property which is used to determine the degree of polarity between two bonded atoms. The relative electronegativities of the elements determine the polarity of a bond. Electronegativity is the ability of an element's atom to attract electrons to itself when it is part of a compound.
Therefore, the correct option is option B.
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Below the time line, list the layers from oldest to youngest
Answer:
F,E,D,C, B, A, G, H, I
Explanation:
I think. It goes bottom to top. the fault probably cause g to happen and maybe h but mattering on what caused what I am not positive
Many fundamental concepts are at the heart of chemistry. Match the description to the name.
Answer:
you dony have a picture for me to match them
Explanation:
A substance has a molar heat of combustion of -810.4 kj/mol. when 0.285 mol of the substance is burned in a calorimeter containing 8.60 kg of water, the increase in water temperature is:
Answer:
6.42 °C
Explanation:
Q = mcΔT
Q = energy gain/release (J)
m = mass (kg)
c = specific heat capacity (J/°C/kg)
ΔT = change in temperature (°C)
Qs = n(ΔH°c)
Qs = energy gained/released from substance (kJ)
n = moles (mol)
ΔH°c = molar heat of combustion (kJ/mol)
m = 8.60
n = 0.285
ΔH°c = -810.4
c (of water) = 4184
Qs = 0.285(-810.4)
Qs = -230.964 (or -230964 J)
Q = 230964
230964 = (8.60)(4184)ΔT
230964 = 35982.4(ΔT)
ΔT = 6.4188... °C → 6.42 °C
which planet is closests to the moon
Answer:
Earth
Explanation:
Answer:
Earth
Explanation:
Hope this helps! Pls give brainliest! Also, please sub to Kgirl633 on yt.
Which of the following is a completely elastic collision? A. a ball rebounds against a wall, reversing its direction, but at only half the speed. B. Two balls collide, stick to each other, and move together after the collision. C. Two balls collide and move at a right angle to each other after the collision at a reduced speed. D. Two balls collide head on, each reversing its direction and traveling at half the speed. E. A ball with velocity v collides with a ball at rest; after the collision the first ball is at rest and the second ball has velocity v. I will mark brainliest
Answer:
Answer E.
For a collision to be completely elastic, there must be NO LOSS in kinetic energy.
We can go through each answer choice:
A. Since the ball rebounds at half the initial speed, there is a loss in kinetic energy. This is NOT an elastic collision.
B. A collision involving sticking is an example of a perfectly INELASTIC collision. This is NOT an elastic collision.
C. A reduced speed indicates that there is a loss of kinetic energy. This is NOT elastic.
D. The balls traveling at half the speed after the collision indicates a loss of kinetic energy, making this collision NOT elastic.
E. This collision indicates an exchange of velocities, characteristic of an elastic collision. We can prove this:
Let:
m = mass of each ball
v = velocity
We have the initial kinetic energy as:
KE = \frac{1}{2}mv^2 + 0 = \frac{1}{2}mv^2KE=21mv2+0=21mv2
And the final as:
KE = 0 + \frac{1}{2}mv^2 = \frac{1}{2}mv^2KE=0+21mv2=21mv2
Answer:
E
Explanation:
hope this helps
What is important about the properties of a substance that has undergone a chemical
change?
The substances created during chemical reactions, on the other hand, do not simply revert to their initial state. The most essential thing to remember is that the makeup of a material does not change when it undergoes a physical change, but it does change when it undergoes a chemical change.
Answer:
the most important thing for you to remember is that in a physical change composition of a substance does not change and in a chemical change the composition of a substance does change
Of the following, ________ is the most volatile. Select one: C2F6 C2H6 C2I6 C2Cl6 C2Br6
Answer:
C2Br6
because bromine is a liquid volatile
According to the forces of attraction and boiling point C₂Br₆ is most volatile as its boiling point is very low.
What are forces of attraction?Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
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The law of conservation of matter states that matter can be neither created nor destroyed. Your friend shows you the following chemical equation: CaCO,CaO+CO, He says that because the oxygen atoms are split between two different molecules in the products, the equation does not support the law of conservation of matter. Is your friend right? Explain your answer.
Answer:
According to conservation of matter, there should be equal amounts of all elements on both the reactant and product side.
Reactant:
1 Ca
1 C
1 O
Product:
1 Ca
1 C
3 O
Therefore, your friend is right because the law of conservation of matter is not followed in this chemical equation.
Explanation:
Which type of monomer combines and forms polypeptides?
A. Nucleic acid
B. Amino acid
C. Fatty acid
D. Monosaccharide
The ___ variable responds to the __ variable and goes on the Y-axis.
1. Dependent, Independent
2. Independent, Dependent
3. Control, Constant
4. Constant, Control
Answer: 1. Dependent, Independent The dependent variable responds to the independent variable and goes on the Y-axis.
Explanation: The independent variable is controlled or manipulated by the experimenter. For example, someone's age might be an independent variable. Other factors (such as what they eat, how much they go to school, how much television they watch) aren't going to change a person's age.The dependent variable is what you are measuring. For example, a test score could be a dependent variable because it could change depending on several factors such as how much you studied, how much sleep you got the night before you took the test, or even how hungry you were when you took it.
How that helps. :)
The dependent variable responds to the independent variable and goes on the Y-axis. Therefore, option A is correct.
What is dependent variable ?In mathematical modeling, statistical modeling, and experimental sciences, there are dependent and independent variables. Dependent variables are so-called because, during an experiment, their values are examined on the assumption or presumption that they are governed by the values of other variables.
the dependent variable on other measurable variables As a result of an experimental manipulation of the independent variable or variables, these variables should change.
What you track in the experiment and what is impacted by it are both considered dependent variables. The independent variable affects the dependent variable's behavior. Because it "depends" on the independent variable, it is known as a dependent variable.
Thus, option A is correct.
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What is always true about lenses?
Answer: They all bend light.
i don't know much about lenses so i hope this helps! :)
what is the continent bellow the world?
Answer:
antarcita
Explanation:
Answer:
What is the continent bellow the world?
Antarctica is the continent below the Earth.The frequency light of 3.52*10-7
Answer:
The speed of light, c, equals the wavelength, λ (pronounced lambda), times the frequency, ν, (pronounced noo).
c=λν
c is a constant. It is usually given as 3.00×108 m/s or 3.00×1010 cm/s rounded to three significant figures.❤
Why do thermistors increase in conductivity when heated? What happens in normal metals? Explain on the atomic level.
Metal conductivity generally goes down or resistivity goes up with temperature goes up.
A sample of CO2 gas at 100 degrees Celsius has a volume of 250 mL at 760 mm Hg. How many moles of CO2 are present
There are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
HOW TO CALCULATE NUMBER OF MOLES:
The number of moles of a sample of gas can be calculated using the following formula:
PV = nRT
Where;
P = pressure of gas (atm)V = volume (L)n = number of moles (mol)R = gas law constant (0.0821 Latm/molK)T = temperature (K)According to this question;
P = 760mmHg = 1 atmT = 100°C = 100 + 273 = 373KV = 250mL = 0.250Ln = ?1 × 0.250 = n × 0.0821 × 373
0.250 = 30.62n
n = 0.250 ÷ 30.62
n = 8.16 × 10-³mol
Therefore, there are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
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If 3.5 mols of P2O3 are formed, how many
moles of P4 reacted?
P2 is 3.5 for p4= 2p2 i.e 2*3.5=7
Answer;561gp203 are required to
produce 10.2 mol H3p03
describe the atomic models above in terms of
a. location of nucleus
b.location of electrons
Consider the energy transfers and transformations that occur when a person rides a bicycle. Describe thi
process by selecting the correct options from the drop-down menus.
Chemical energy is transformed into
energy in the person's muscles.
Kinetic energy is
from the person's legs to the pedals.
Kinetic energy is
thermal energy due to friction when the wheels get warm.
DONE
Answer:
b,a,b
Explanation:
The energy transfers and transformations that occur are kinetic energy is from the person's legs to the pedals and thermal energy due to friction when the wheels get warm.
What is law of conservation of energy?The law of conservation of energy states that energy can neither be created nor destroyed but can be converted from one form to another.
The energy transfers and transformations that occur when a person rides a bicycle are:
Kinetic energy is from the person's legs to the pedals Thermal energy due to friction when the wheels get warmLearn more about conservation of energy here: https://brainly.com/question/24772394
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AgNO3 is a useful chemical that has many applications and can undergo a variety of reactions. In the following examples, balance each equation if necessary and then identify what type of reaction it represents. i. AgNO3 + Cu —>Cu(NO3)2 + Ag ii. AgNO3 —> Ag +O2 + NO2 iii. AgNO3 + KCI —> AgCI + KNO3 iv. Ag+ +I- +Agl
The balance chemical equation and the type of reaction of AgNO₃ and the other compounds can be represented as follows;
2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag (single displacement )
2AgNO₃ → 2Ag + O₂ + 2NO₂ (decomposition reaction)
AgNO₃ + KCI → AgCI + KNO₃(double displacement reaction)
2Ag + I₂ → 2AgI (synthesis reaction)
AgNO₃ + Cu → Cu(NO₃)₂+ Ag
The balance equation is as follows:
2AgNO₃ + Cu → Cu(NO₃)₂ + 2AgThis is a single displacement (substitution) reaction. The Copper substance displaced silver from it compound.
AgNO₃ → Ag + O₂ + NO₂
The balance equation is represented as follows:
2AgNO₃ → 2Ag + O₂ + 2NO₂The reaction is a decomposition reaction. Silver nitrate was decompose to it individual constituent.
AgNO₃ + KCI → AgCI + KNO₃
The balance equation is represented as follows:
AgNO₃ + KCI → AgCI + KNO₃The reaction is a double displacement reaction. The anions and cations of two different compound switch places, forming two entirely different compounds.
Ag + I₂ → AgI
The balance equation is as follows:
2Ag + I₂ → 2AgIThe reaction is a synthesis reaction. The individual elements combined to form a compound.
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convert 3.79 x 10^24 atoms of sodium to grams
mol = 3.79 × 10^24/6.02 × 10^23 = 6.296 mol
mass = 6.296 × 23 = 144.808 grams
Which of the following ideas did Greek philosopher Democritus contribute to the atomic theory?
A. Matter is composed of only one kind of particle, which can be easily destroyed.
B. Every element has a specific type of atom, which remains the same size in all forms of matter.
C. All matter is composed of small particles, which combine to make larger objects.
D. Each object is made up of one atom, which varies in size from very small to very large.
I will mark the correct answer the brainliest
Answer:
c. all matter is composed of small particles,which combine to make larger objects
