Answer:
The correct option is A
Explanation:
Water from a river is used for many activities in a community. These activities could include (but not limited to) tourism, drinking for animals, local transport, irrigation for nearby farming, recreation (as in swimming), habitat for some living organisms among others. Rivers are not limited by what limits the influence of oceans such as taste (it's saltiness, which cannot be used in farming also) and wave current.
which is one way that water helps living things?
a temperature regulation
b. oxygen transportation
c. heat absorption
d. nutrient production
Calculate the number of moles of Al 2
O3
that are produced when 0.60 mol of Fe is produced in the following
reaction.
2Al(s) + 3FeO(s) 3Fe(s) + Al2
O3
(s)
The number of moles of Al₂ O₃ : 0.2
Further explanationThe reaction equation is the chemical formula of reagents and product substances
A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products
Reaction
2Al(s) + 3FeO(s) ⇒ 3Fe(s) + Al₂ O₃(s)
0.6 mol of Fe = 0.6 mol of FeO
mol of Al₂ O₃ : mol of FeO = 1 : 3
[tex]\tt \dfrac{1}{3}\times 0.6=0.2[/tex]
What is nuclear fusion and what does it produce in a star?
Answer:
Energy
Explanation:
Nuclear fusion is the process of combining atoms to make heavier atoms. This releases a huge amount of energy and it is what stars like our sun use to create energy.
If 0.0369 mol CaCl2 is dissolved in water to make a 0.340 M solution, what is the volume of the solution
Answer:
The correct answer is 0.11 L
Explanation:
From the problem, we have the following data:
moles CaCl₂= 0.039 mol
molarity = 0.340 M = 0.340 mol CaCl₂/L
According to this, the solution has 0.340 mol of CaCl₂ in 1 L. If the total number of moles is 0.0369, we can find the volume as follows:
V= moles/molarity = 0.0369 mol x 1 L/0.340 mol = 0.108 L ≅ 0.11 L
For the chemical reaction
2 NaOH + H2SO4
→
Na, SO4 + 2 H20
how many moles of sodium sulfate (Na2SO4) are produced from 4.0 mol of sodium hydroxide (NaOH)?
m
Answer:
2 moles.
Explanation:
2NaOH + H2SO4 --> Na2SO4 + 2H2O
This shows that 2 moles of NaOH give 1 mole of Na2SO4.
So 4 moles produces 2 moles of Na2SO4.
Terry usually rides his bike at 15 mph. If his riding speed is reduced by 3 mph, how far can he ride in 1.7 hours? ___miles
Answer:
20.4 miles.
Explanation:
We know he usually rides his bike at 15mph, and if we subtract 3 from that we get 12 miles per hour. Now if we multiply by the amount of time (1.7 hours) we'll find our answer. 12 x 1.7 = 20.4
Answer:
20.4
Explanation:
I just had the question.
100.0 g H2SO4 =
? mole H2SO4
Answer:
sulfuric acid ..............
Calculate the speed of the car at each checkpoint by dividing the distance between each checkpoint in meters by the change in time. Record your answers in Table C of your Student Guide. The speed at the first quarter checkpoint is m/s. The speed at the second quarter checkpoint is m/s. The speed at the third quarter checkpoint is m/s. The speed at the finish line is m/s.
The speed of the car at each checkpoint cannot be determined because the parameter is not given.
What is the speed of a moving car?For a moving car, the speed can be defined as the change magnitude in the position of a car or the distance traveled by the car within a specified time.
Mathematically;
[tex]\mathbf{speed = \dfrac{distance}{time}}[/tex]
From the information given; the distance at each checkpoint can be calculated by finding the difference in distance between the previous checkpoint and subsequent checkpoint divided by the change in time.
i.e
[tex]\mathbf{speed = \dfrac{d_A - d_B}{\Delta t}}[/tex]
where:
[tex]\mathbf{d_A-d_B}[/tex] = distance between checkpoints A and BLearn more about the speed of a car here:
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answer is below . . .
Please answer! If you answer you get brainlist :D
Answer:
A test variable is a user-defined, name-value pair that stores and refers to information throughout a test and between tests. For example, in a study looking at how tutoring impacts test scores, the dependent variable would be the participants' test scores, since that is what is being measured...
The control group is defined as the group in an experiment or study that does not receive treatment by the researchers and is then used as a benchmark to measure how the other tested subjects do. For example, The control group is used in an experiment as a way to ensure that your experiment actually works. Your experimental group would be given the Gatorade and your control group would be given regular water. The conditions must be exactly the same for all members of the experiment.
A limiting factor is anything that constrains a population's size and slows or stops it from growing. Some examples of limiting factors are biotic, like food, mates, and competition with other organisms for resources. Limiting factors are usually expressed as a lack of a particular resource.
Infectious agents commonly spread through the direct transfer of bacteria, viruses, or other germs from one person to another. This can happen when an individual with the bacterium or virus touches, kisses, or coughs or sneezes on someone who isn't infected.
Explanation:
10. What does a full moon look like from earth? *
Your answer
Answer:
like a circle
Answer:
it would look white and its a circle
Explanation:
pLEASE MARK BRAINLIEST
How many valence electrons does the following element have?
Whats the answer chemistry
Answer:
8
Explanation:
how is coal usually used
Answer:
Coal is primarily used as fuel to generate electric power in the United States.
Explanation:
A 0.216 g sample of carbon dioxide, CO2, has a volume of 507 mL and a pressure of 470 mmHg. What is the temperature of the gas in kelvins?
Answer:
The temperature of the gas is 876.69 Kelvin
Explanation:
Ideal gases are a simplification of real gases that is done to study them more easily. It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.
The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:
P*V = n*R*T
where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas.
In this case:
P= 470 mmHgV= 570 mL= 0.570 Ln= 0.216 g= 0.0049 moles (being the molar mass of carbon dioxide is 44 g/mole)R= 62.36367 [tex]\frac{mmHg*L}{mol*K}[/tex]T=?Replacing:
470 mmHg*0.570 L= 0.0049 moles* 62.36367 [tex]\frac{mmHg*L}{mol*K}[/tex] *T
Solving:
[tex]T=\frac{470 mmHg*0.570 L}{0.0049 moles* 62.36367\frac{mmHg*L}{mol*K} }[/tex]
T= 876.69 K
The temperature of the gas is 876.69 Kelvin
If 2.50 ml of vinegar requires 34.50 ml of 0.0960 M NaOH to reach the equivalence point in a titration, how many grams of acetic acid are in 500.0 ml of this vinegar? Density of vinegar=1.01 g ml
Grams of acetic acid in 500 ml vinegar=39.744 g
Further explanationTitration (equivalence point⇒mol acid(CH₃COOH)=mol base(NaOH))
M₁V₁n₁=M₂V₂n₂(n=valence acid/base, for CH₃COOH and NaOH=1)
[tex]\tt M_1\times 2.5\times 1=0.0960\times 34.5\times 1\\\\M_1(acetic~acid)=1.3248~mol/L[/tex]
For MW CH₃COOH = 60 g/mol, mass of acetic acid in 1 L :
[tex]\tt 1.3428~mol/L\times 60~g/mol=79.488~g/L[/tex]
for 500 ml :
[tex]\tt 79.488\times 0.5~L=39.744~g[/tex]
The mass of vinegar present in 500mL of solution is 39.6 g.
Concentration of acid (CA) = ?
Volume of acid(VA) = 2.50 ml
Concentration of base (CB) =0.0960 M
Volume of base (VB) = 34.50 ml
Number of moles of acid = 1
Number of moles of base = 1
Equation of the reaction;
CH3COOH (aq) + NaOH(aq) ------> CH3COONa(aq) + H2O(l)
From CAVA/CBVB = NA/NB
CAVANB = CBVBNA
CA = CBVBNA/VANB
CA = 0.0960 × 34.50 × 1/2.50 × 1
CA = 1.32 M
Number of moles = concentration × volume
Number of moles = 1.32 M × 500/1000
Number of moles = 0.66 moles
Number of moles = mass/molar mass
Mass = Number of moles × molar mass
Molar mass of acetic acid = 60 g/mol
Mass = 0.66 moles × 60 g/mol
Mass = 39.6 g
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what is the iupac name of this compound. CH3-C H -CH2- CH3
What name should be used for the ionic compound Cu(NO3), ?
O copper nitrate
O copper(1) nitrate
copper(II) nitrate
O copper(III) nitrate
Answer:
copper nitrate
Explanation:
copper nitrate
Answer:
Copper (ll) nitrate or C
Explanation:
Which of the following is an example of chemical weathering?
wind breaking down rock
plant roots splitting rocks
acid dissolving limestone
water breaking rocks
Answer:
the answer is C acid dissolving limestone
Explanation:
Answer:
the answer is C acid dissolving limestone
Explanation:
The chemicals in the water break down the rocks, so water breaking rocks is an example of chemical weathering :) Also, acids are a form of chemical weathering, as the chemicals dissolve the limestone :) Hope this helped!!
Which of the following substances would you expect to have a low melting point?
A. carbon dioxide
B. silicon dioxide
C. lithium chloride
D. calcium bromide
Ionic compounds have higher melting point than covalent compounds.
Carbon dioxide have lower melting point (-56.6 °C) among the given compounds.
What is melting point?Melting point is the temperature at which the substance melts into liquid thus at this temperature its solid state and liquid state are in equilibrium. Melting point is depend upon the bond type and mass of the compound.
Ionic bonds are stronger than covalent bonds and hence ionic compounds have higher melting point than covalent compounds. Hence, lithium chloride and calcium bromide have higher melting point.
Silicon is bigger than carbon thus silicon dioxide melts at higher temperature. Carbon dioxide is purely covalent and melts at negative temperatures.
Hence, the compound with lower melting point here is carbon dioxide thus, option A is correct.
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A peak elutes from an HPLC column 17.7 cm in length in 11.1 min. What would be the width at half‑height of the peak (in seconds) if the plate height were 8.68 μm?
Answer:
10.98 s
Explanation:
To solve this problem we first use the formula:
H = L/NWhere:
H = Plate height (8.68 μm, or 8.68x10⁻⁶m)L = Column length (17.7 cm, or 0.177 m)N = Number of theoretical plates (unknown)And solve for N:
N = 0.177 m / 8.68x10⁻⁶mN = 20392 platesThen we use the formula:
N = 5.54*[tex](\frac{t_r}{W_{0.5}})^2[/tex]Where:
N is the number of theoretical plates previously calculated. tr is the retention time (11.1 min, or 666s)W₀.₅ Is the width at half-height (unknown)And solve for W₀.₅:
W₀.₅ = 10.98 swhat happens when the temperature of gas is increased
Answer:
If you heat a gas you give the molecules more energy so they move faster.
Explanation:
7. A student has a 25 g sample of gas in a container at STP and adds another 7
g of the gas while keeping the pressure constant, what is the new temperature in
degrees Celsius?
Answer:
New temperature t2 = [1.28T− 273.15]° C
Explanation:
Given:
Volume v1 = 25 gram
New volume v2 = 25 + 7 = 32 gram
Constant pressure = p
Temperature t1 = T
Find:
New temperature t2
Computation:
Pv1/t1 = Pv2/t2
25 / T = 32 / t2
t2 = 1.28T
New temperature t2 = [1.28T− 273.15]° C
1.(03.02 LC)
Which of the following best defines weather? (3 points)
The atmospheric conditions at a particular time.
i did the test.
Answer:
the atmospheric conditions at a particulur time
Explanation:
1. Which of the following statements describe cations? Select all that apply.
Positively charged ions.
Negatively charged ions.
They have lost electrons.
They have gained electrons.
Ions can be made by single element or covalently bonded group of elements. The covalently bonded group of elements is called polyatomic ions or polyatomic atoms. The correct option are option A,C.
What is Ions?
Any species that contain charge whether it is positive charge or negative charge is called ions. The example of polyatomic ions are sulfate, phosphate, nitrate etc.
Cation is the species that loose electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral, the charge over cation and anion is also called oxidation state.
Therefore the correct option are option A,C.
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What is the wavelength of a wave releasing an energy of 3.713 x 10-17 J?
Answer:
C = λν E = hν C = 3.00 x 108 m/s h = 6.626 2 x 10-34 J-s (or J/Hz) 1 eV = 1.602 x 10-19 J
Explanation:
a 500 ml aqueous solution of na3po4 was prepared using 82g of the solute. what is the molarity
Answer:
1 M
Explanation:
The molarity of a solution, M, is a measure of the concentration of that solution and it refers to the number of moles of solute (mol) per liter (L) of solution. The molarity (M) can be calculated using the formula:
M = number of moles (n) /volume (V)
In this question, a 500 ml aqueous solution of Na3PO4 was prepared using 82g of the solute.
Molar mass of Na3PO4 = 23(3) + 15 + 16(4)
= 69 + 31 + 64
= 164g/mol
Mole = mass/molar mass
mole = 82/164
mole = 0.5 mol
Volume in Litres (L) = 500 ml ÷ 1000 = 0.500L
Therefore, Molarity (M) = 0.5/0.500
Molarity = 1 M or 1 mol/L
The molarity of the solution is 1 M
From the question,
We are to determine the molarity of the solution.
First, we will determine the number of moles of the solute (Na₃PO₄) present
Mass of Na₃PO₄ = 82 g
Using the formula
[tex]Number\ of\ moles = \frac{Mass }{Molar\ mass}[/tex]
Molar mass of Na₃PO₄ = 163.94 g/mol
∴ Number of moles of Na₃PO₄ present = [tex]\frac{82}{163.94}[/tex]
Number of moles of Na₃PO₄ present = 0.500 moles
Now, for the molarity of the solution
Using the formula
[tex]Molarity = \frac{Number\ of\ moles}{Volume}[/tex]
Volume of the solution = 500 mL = 0.5 L
∴ Molarity of the solution = [tex]\frac{0.500}{0.5}[/tex]
Molarity of the solution = 1 M
Hence, the molarity of the solution is 1 M
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Dennie wanted to see if crayfish preferred one kind of food over another. He gave one group of crayfish plants, both living and dead, to eat. He gave the other group insects, living and dead, to eat. What is the independent variable in Dennie's experiment? a)type of food b)weight of crayfish c)typeof water used d)age of crayfish
Answer:
A) type of food.
Which is an example of a beneficial mutation?
one that changes the color of a rabbit, allowing it to hide from predators.
one that results in lighter flower petal colors without changing the plant’s ability to reproduce
one that causes a person’s body to produce thick mucus that clogs the lungs
one that makes it easier for a corn plant to contract a disease
Answer:
A
Explanation:
Answer: a
Explanation: one that changes the color of a rabbit, allowing it to hide from predators.
What values of ℓ are possible for a shell with n = 4
Answer:
0, 1, 2, 3
General Formulas and Concepts:
Chemistry - Atomic Structure
Principal Energy Level n (1 to ∞)Angular Momentum ℓ (n - 1)Magnetic mℓElectron Spin msExplanation:
Step 1: Define quantum number
Principal Energy Level n = 4
Step 2: Define ℓ
ℓ is the Angular Momentum. Its values start at 0, 1, 2, 3...
It is the Principal Energy Level n minus 1 (n - 1).
Step 3: Find
n = 4
ℓ = 4 - 1 = 3
Therefore, out angular momentum values can be 0, 1, 2, 3. These correlate to s, p, d, f sublevels.
. A 20.0 % by mass solution of phosphoric acid (H3PO4) in water has a density of 1.114 g/mL at 20°C. What is the molarity of this solution?
The molar mass of phosphoric acid (H3PO4) is 97.99 g.
Answer:
2.273M
Explanation:
What is the definition of molarity.
M = mols/L. So that's what we need to determine.
How much does a L weigh? That's
1.114 g/mL x 1000 mL = 1114 grams. Simple enough, eh?
How much of that 1114 g is H3PO4. It says it is 20% by mass, therefore, 1114 g x 0.20 = 222.8 g.
How many mols are there in 222.8 g H3PO4? That's mools = grams/molar mass = 222.8/98 = 2.273 mols.
The definition of M is what? M = mols/L. And you have 2.273 mol/L; that must be the molarity.
The formula is
density g/mL x 1000 mL x mass% x (1/molar mass) = M
1.114 x 1000 x 0.20 x (1/98) = 2.273 M.
How many kJ are required to completely vaporize a 25.0 gram sample of water at 100°C? general formula:
Answer:
56500J
Explanation:
Given parameters:
Mass of water = 25g = 0.025kg
Temperature of the water = 100°C
Unknown:
Amount of heat required to vaporize the water = ?
Solution:
The amount of heat required to vaporize the water is a function of the mass of the water and the latent heat of vaporization of water.
H = mL
H is the amount of heat
m is the mass
L is the latent heat of vaporization of water = 22.6 x 10⁵J/Kg
H = 0.025 x 22.6 x 10⁵ = 56500J