Answer:A
Explanation:
Answer:
m
Explanation:
What body system changes the food we eat into energy?
Answer:
We need food to fuel our bodies for energy, growth and repair. The digestive system converts the foods we eat into their simplest forms, like glucose (sugars), amino acids (that make up protein) or fatty acids (that make up fats).Explanation:
hopes its right
A 20.0 mL of 0.27 M solution of the salt NaA has a pH of 8.70.
a) Calculate the pk, value of the acid HA.
(Correct to 3 sig. fig)
b) Calculate the pH of a solution containing 0.3 M HA and 0.1 M NaA.
(Correct to 3 sig. fig)
Thanks!!
Answer:
a) 3.969
b) 3.487
Explanation:
Given data:
m = 0.27 M
pH = 8.7
a) Calculate PKa of acid HA
pH value = 1/2 ( Pkw + Pka + log C )
8.7 * 2 = 14 + log C + Pka
17.4 = 14 + log ( 0.27 ) + Pka
∴Pka = 17.4 - 14.5686 = 3.9686 ≈ 3.969
b) Calculate the pH of solution
pH = pKa + log ( salt / acid )
= 3.9686 + log ( 0.1 / 0.3 )
= 3.487
A mixture of gases in a container has a pressure of 1275.5 mm Hg. If the pressure of CO2 gas is 335.3 mm Hg and the pressure of N2 gas is 418.0 mm Hg, what is the pressure of O2 gas.
You are on vacation with your family up in the mountains. Your friend is on vacation near the equator by the ocean. Explain which climate will experience the most precipitation.
A.) Both climates will have the same amount of precipitation.
B.)The ocean climate will have less precipitation because it is close to sea level.
C.)The climate around the equator will have more precipitation because it is very hot.
D.)The mountain climate will have more precipitation because it increases with elevation.
Answer:
I gonna go wit number C
Explanation:
Answer: C
Explanation:
Which one of the following compounds is insoluble in water?
a) Na2CO3
b) K2SO4
c) Fe(NO3)3
d) ZnS
Answer: ZnS
Explanation: usually salts of alkali metals are well soluble in water.
Also most nitrates are well soluble.
Sulfides of transition metals are generally insoluble in water
Zinc sulfide is a compound which is insoluble in water as it is a sulfide salt of transition metal which are water-insoluble.
What is a compound ?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
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PLEASE HELPPPPPPPP
Why do organic materials decompose so slowly inside of a landfill? List 3 factorsthat are required for biodegradation
Answer:
3 factors that are required for biodegradation are
a) Appropriate moisture
b) Oxygen supply
c) Stable condition
Explanation:
For biodegradation in a landfill, following conditions are essential –
a) Appropriate moisture
b) Oxygen supply
c) Stable condition
Contrast to above three conditions, the waste in landfill is kept dry, devoid of oxygen supply, and stirred continuously due to which the organic matter mummify instead of decomposing.
How many moles of a gas would occupy 11.4 L at 273K and 2.00 atm?
Answer:
1.02mol
Explanation:
Using the general gas equation below;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
T = temperature (K)
According to the information provided in this question,
P = 2.0 atm
V = 11.4L
T = 273K
n = ?
Using PV = nRT
n = PV/RT
n = 2 × 11.4/ 0.0821 × 273
n = 22.8/22.41
n = 1.017
n = 1.02mol
This is agree or disagree I need help ASAP!!
Is a 3.3% solution dilute or concentrated?
Dilute
Concentrated
Answer:
Dilute
Explanation:
A concentrated solutions is a one which has relatively large amount of dissolved solute in the solution whereas a dilute solution is a one which has relatively lower concentration of dissolved solute.
In the given solution there is only 3.3% of solute. So, we can say that the given solution is a dilute solution. However, these terms are relative.
HELP!! 30 POINTS!!!! What does the energy graph look like for this reaction??
C3H8+5O2 -> 3CO2+4H2O
I have the data, I just need to know how to make the graph, please!!
total enthalpy of reactants= -103.85
total enthalpy of products= =-2147.81
=-2043.96 kJ/mol exothermic reaction
Answer:
Bottle Nose Dolphin ummmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
Explanation:
HELP MY FRIEND NEEDS HELP WITH THIS!!!!!!
can somebody please help? I'm asking for a friend
If 263 ml of a gas is collected at 47°c and 2.77 atm, what will the final temp be in C if the volume decreases to 195 mL and the pressure increases to 3.87 atm?
Answer:
Oh hey sorry, they deleted my account again..
Explanation:
can someone pls help me answer e-j given the instructions above, thank youu
Answer:
e. Not balanced C and O
f. Balanced
g. Balanced
h. Unbalanced Al and O
i. Balanced
j. Balanced
Second part
a. 2
b. 2 and 2
c. For O is 5 while H20 is 4
Explanation:
Please mark as brainliest
Given : 4.50 molte
How many moles of ammonia would you get if 4.50 moles of hydrogen gas
reacted
Which of the following compounds, sodium bicarbonate or water, should be used to extinguish a grease fire?
Answer:Douse the fire with baking soda: The chemical compound sodium bicarbonate, commonly called baking soda, is effective for extinguishing this type of fire. It takes a lot of baking soda to smother a grease fire, so pour it on while the flames are still small for the greatest effect
Explanation:
The grease fire has been put down by the addition of sodium bicarbonate as the extinguisher.
Grease fire has been defined as the fire that has been started with the over heating of the cooking oil at home. The fire has been started with the burning of the flammable liquids.
Extinguishing Grease fireThe fire in the cooking oil has been controlled with the addition of the sheet over the fire and turning off the flame.
The addition of water to grease fire results in the splashing of water over the fire and the spreading, resulting in the hazardous effects.
The sodium bicarbonate or baking soda has been used to put down grease fire.
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A sample of neon gas is at a temperature of 60°C and has a volume of 300 cm. What is the volume of the gas if it is heated to 100°C at a constant pressure?
Answer:
336.04 cm
Explanation:
T1 = 60+273 = 333K
T2 = 100+273 = 373K
V2 = (V1×T2)/T1
V2 = 300×373/333
V2 = 336.04 cm
How much water would I need to add to a 175 mL of a 0.45 M KOH solution to make a 0.2 M solution?
Answer:
393.75mL
Explanation:
We know that
C1V1= C2V2
where C = centration, V= volume
C1= 0.45 M
V1= 175 mL = 0.175 L
C2 = 0.2M
⇒V2= C1V1/C2
⇒V2 = 0.175×0.45/0.2
=0.39375L
Therefore, amount of water needed= 393.75mL
Which statement correctly describes electrochemical cells?
A. Electrochemical cells involve only oxidation reactions.
B. Electrochemical cells involve only reduction reactions.
C. Electrochemical cells involve oxidation-reduction reactions.
D. Electrochemical cells do not involve oxidation-reduction reactions.
Answer: C. Electrochemical cells involve oxidation-reduction reactions.
Explanation: Oxidation occurs at the anode, and reduction occurs at the cathode.
help pls this is physical science (9th grade )
Answer:
mamamkalalllaamakkaoakmaa
Give the following acid/base reaction:
HI(aq) + NH3(aq) ↔ NH4+(aq) + I-(aq)
Determine which substance is the acid, base, conjugate acid, and conjugate base.
Column A Column B:
1. Acid 1: I-
2. Base 2: HI
3. Conjugate base 3: NH3
4. Conjugate acid 4: NH4+
Answer:
6=100
Explanation:
whats the most effective way to study when your teachers dont tell you about a test until the day before the test.? help! currently struggling
Explanation:
You should read the most important questions properly and you should look your syllabus of test.
You should read old questions of test
that were already asked.
how many Na atomd are shown in the reactants
Answer:
On the reactant side, there are two H atoms and two O atoms
The equation A+ BX à AX + B is the general equation for a
Answer: d
Explanation:
took the test
Determine from the balanced chemical reaction if
the derived mole ratio is correct or incorrect.
2FeBr3 + 3Na2S → Fe2S3 + 6NaBr
2 moles FeBra
3 moles Na2S
Answer:
Correct
Explanation:
According to the balanced chemical reaction, 2 mol FeBr3 are consumed for every 3 mol Na2S consumed.
A balanced equation obey the law of conservation of mass. The coefficients are the numbers which are added to balance the chemical equation. Here the given mole ratio is correct.
What is a balanced equation?An equation in which the number of atoms of reactants and products on both sides of the equation are balanced is defined as the balanced chemical equation. The coefficients which are added in front of the formula of each component represents the number of the species.
A molar ratio denotes the ratio between the amounts in moles of any two compounds involved in a balanced chemical reaction. By comparing the coefficient of each component, the mole ratio can be determined.
Here for the given reaction, for every 3 moles of Na₂S consumption 2 moles of FeBr₃ is also consumed. So the molar ratio of Na₂S to FeBr₃ is 2/3. Molar ratios are used as the conversion factors between products and reactants in many chemistry problems.
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What does the symbol NaCl(aq) mean?
Answer:
The (aq) means that the NaCl is dissolved in water.
Explanation:
Answer:
A water-based solution of sodium chloride
Explanation:
ck12
In a solution, litmus is blue. The pH of the solution could be
1 10 2 2 3 3 4 4
Answer:
absotutately right
Explanation:
What is the pH color scale?
The pH scale runs from 0 to 14, with each number assigned a different color. At the bottom of the scale sits red, which represents the most acidic, and a dark blue at its opposite end represents 14 and alkalinity. In the middle zone, the pH scale becomes neutral
The pH of the solution could be 10. The basic solution has a pH value of more than 7.
What is pH?pH is a measure of acidity and basicity of aqueous solution.The range of pH goes from 0 - 14, with 7 being neutral.pH of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base.pH is the measure of the relative amount of free hydrogen and hydroxyl ions in aqueous or other solutions.Litmus paper helps us qualitatively determine a substance as an acid or base. For any substance to be a base, blue litmus must remain blue.
The pH scale ranges from 0 to 14 and anything below 7.0 is acidic and anything above 7.0 is alkaline or basic.
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Plants and animals need to protect themselves to survive. Select the statement that best describes the adaptions of animals and plants.
How could a scientist use a sedimentary rock to provide evidence that the right k cycle is a valid scientific model
Answer:
By closely observing the sedimentary rock and the presence of organic materials and mineral grains in sedimentary rocks
Explanation:
The rock cycle explains how the three types of rock are formed over time from each other.
To use a sedimentary rock to prove that the rock cycle is a valid scientific model is by, closely observing the sedimentary rock. when the sedimentary rock is closed observed the principle of superposition will be seen ( i.e. younger segments deposited on top ), the presence of organic materials and mineral grains that can be found in Igneous or Metamorphic rocks can also be seen and this shows that Sedimentary rocks pass through the rock cycle. hence this proves that the rock cycle is a valid scientific model overtime
When filling a weather balloon with gas you have to consider that the gas will expand greatly as it rises and the pressure decreases. Let's say you put about 10.0 moles of He gas into a balloon that can inflate to hold 5000.0L. Currently, the balloon is not full because of the high pressure on the ground. What is the pressure when the balloon rises to a point where the temperature is -10.0°C and the balloon has completely filled with the gas.
Answer:
0.0432 atm
Explanation:
Step 1: Given data for when the balloon is full
Moles of Helium (n): 10.0 molVolume of the balloon (V): 5000.0 LTemperature (T): -10.0 °CIdeal gas constant (R): 0.0821 atm.L/mol.KStep 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15
K = -10.0°C + 273.15 = 263.2 K
Step 3: Calculate the pressure of He in the balloon
We will use the ideal gas equation.
P × V = n × R × T
P = n × R × T/V
P = 10.0 mol × (0.0821 atm.L/mol.K) × 263.2 K/5000.0 L = 0.0432 atm
Which body system includes the heart?
A pH scale has how many sections on it?
Answer:
0-14
Explanation: