Answer:
d. 7.7x10^23 molecules
Explanation:
Given the following data:
Mass of water (H2O) = 23g
To find the number of molecules;
First of all, we would determine the number of moles;
[tex] Number \; of \; moles = \frac {mass}{molar mass} [/tex]
Molar mass of water (H2O) = (1 * 2) + 16 = 18 g/mol
Substituting into the equation, we have
[tex] Number \; of \; moles = \frac {23}{18} [/tex]
Number of moles = 1.2778 moles
Now, to find the number of water molecules;
We know that Avogadro constant is equal to 6.02 * 10^23 mol¯¹
Number of water molecules = number of H2O moles * Avogadro constant
Substituting into the equation, we have;
Number of water molecules = 1.2778 × 6.02 * 10^23
Number of water molecules = 7.7 × 10^23 atoms.
When riding a roller coaster, you go up and down many hills. As you get to the top of a roller coaster, what energy change is taking place?
A. potential energy is changed into kinetic energy
B. kinetic energy is changed into potential energy
C. chemical energy is changed into heat energy
D. heat energy is changed into chemical energy
Answer:
A.
Explanation:
The potential energy of the roller coaster increases as the coaster goes up a hill and can be converted to kinetic energy.
If 25.00 mL of 6.00 M HCl is transferred by pipet into a volumetric flask and diluted to 5.00 L, what is the molarity of the diluted HCl?
Answer:
0.03 M
Explanation:
The computation of the molarity of the diluted HCI is given below:
As we know that
(M1) × (V1) = (M2) × (V2)
Now
(M2) = {(M1) × (V1)} ÷ (V2)
or
Molarity of the diluted HCl,(M2) is
= {6 × 25} ÷ 5000
= 0.03 M
Question 6: Describe an experiment for determining the position in the reactivity series for
copper, iron and magnesium. Include safety measures and the equipment you would use (5
Marks) *
(5 Points)
Enter your answer
BI
(hp)
Answer: BI
because of rection progress
Explanation:
Observe: Click Reset. Select the Gas collection setup. Chemists use this apparatus to collect any gases produced in the reaction. From the reaction flask, gases travel through a long tube and into a cylinder of water. As gases bubble into the cylinder, the water is displaced (removed) until the cylinder is filled with gas. Was any gas produced in the reaction? How do you know? I WILL GIVE POINTS AND BRAINLIEST IF YOU ANSWER CORRECTLY. THANK YOU :)
Answer:
Due to displacement of water.
Explanation:
If the water is displaced in the cylinder it means that the gas is produced in the reaction while on the other hand, if the water is not displaced in the cylinder so it means that the reaction does not produces any gas yet. So we can say that the displacement of waters indicates or shows us whether the gas is produced in the reaction or not.
If you have 0.36mol C that reacts with excess CuO, how many atoms do you have of Cu?
Calculate [H+] and [OH-] as required for each of the following
solutions at 25 °C, and state whether the solution is neutral, acidic,
or basic.
a. 1.0x 10-5 MOH-
Q
b. 1.0x 10-7 MOH-
c. 10.0 MH+
Explanation:
The relationship between H+ and OH- at 25 °C is given as;
[H+} x [OH-] = 1.0 x 10-14 M
a. 1.0 x 10-5 M OH-
[OH-] = 1.0 x 10-5 M
[H+] = 1.0 x 10-14 M / [OH-] = 1.0 x 10-14 M / 1.0 x 10-5 M
[H+] = 1.0 x 10^(-14+5)
[H+] = 1.0 x 10^(-9)
pH = - log [H+]
pH = - log [10^(-9)]
pH = 9
This is a basic solution
b. 1.0 x 10-7 M OH-
[OH-] = 1.0 x 10-7 M
[H+] = 1.0 x 10-14 M / [OH-] = 1.0 x 10-14 M / 1.0 x 10-7 M
[H+] = 1.0 x 10^(-14+7)
[H+] = 1.0 x 10^(-7)
This is a neutral solution since [H+] and [OH-] are equal
c. 10.0 M H+
[H+] = 1.0 x 10 M
[OH-] = 1.0 x 10-14 M / [H+] = 1.0 x 10-14 M / 1.0 x 10 M
[OH-] = 1.0 x 10^(-14-1)
[OH-] = 1.0 x 10^(-15)
pH = - log [H+]
pH = - log [10^(1)]
pH = -1
This is an acidic solution since it has a pH of -1
How many moles of Ca(OH)2 are needed to make 2.5 moles of CaCl2?
Explanation:
CaCl2 ⇄ Ca-²+2Cl-¹
1mole⇄1mole+2moles
So from above ..
1mole CaCl2 produce 1mole Ca-² & 2 moles of Cl-².
For 2.5 moles we multiply the above chemical eq. With 2.5
2.5CaCl2⇄2.5Ca-²+5Cl-¹
So from 2.5 moles of CaCl2 we get 2.5 mole calcium ion and 5 moles chloride ion…
What do chemists study?
A. The properties of matter and how matter changes
B. How matter and energy interact
C. Mathematical principles
D. Living things
SUBMIT
A. The properties of matter and how matter changes.
Answer: A. the properties of matter and how matter changes
Explanation:
just got it right
Explain the 3 steps required to determine the molecular formula.
Answer:
The steps involved in determining a Molecular Formula are: Find the mass of the empirical formula. Divide the molecular mass by the mass of the empirical formula. Multiply each subscript in the empirical formula by the answer.
Explanation:
Which product of photosynthesis is the food?
Oxygen
Carbon Dioxide
Water
Glucose
Answer:
Oxygen
Explanation:
In photosynthesis, solar energy is harvested and converted to chemical energy in the form of glucose using water and carbon dioxide. Oxygen is released as a byproduct.
Answer:
the answer is a) oxygen
Explanation:
when plants are performing photosynthesis they take in carbon dioxide given out by humans and animals which is the balance of nature and give out oxygen. in this process sunlight and chlorophyll is also involved!!!!
I hope I cleared your doubt :)
What is the freezing point (in degrees Celcius) of 4.14 kg of water if it contains 235.1 g of butanol, C 4 H 9 O H
Answer:
Explanation:
Molal freezing point depression constant of butanol Kf = 8.37⁰C /m
ΔTf = Kf x m , m is no of moles of solute per kg of solvent .
mol weight of butanol = 70 g
235.1 g of butanol = 235.1 / 70 = 3.3585 moles
3.3585 moles of butanol dissolved in 4.14 kg of water .
ΔTf = 8.37 x 3.3585 / 4.14
= 6.79⁰C
Depression in freezing point = 6.79
freezing point of solution = - 6.79⁰C .
A car travels 75 mi/hr. How many hours will it take to travel 837 km? (Pick the answer closest to the correct answer,
1.61 km=1 mile)
Answer:
6.9 hours
Explanation:
In order to solve this problem we'll convert 837 km to miles (another option would be to convert 75 mi/hr to km/hr). To make said conversion we'll use the given conversion factor:
837 km * [tex]\frac{1mi}{1.61km}[/tex] = 519.88 miFinally we calculate the time required to travel said distance at a constant speed of 75 mi/hr:
519.88 mi ÷ 75 mi/hr = 6.9 hrThe amount of time it would take to travel 837 km is equal to 7 hours.
Given the following data:
Speed = 75 mi/hr.Distance = 837 km.To determine the amount of time it would take to travel 837 km:
How to calculate time.First of all, we would convert the value of the distance in kilometers to miles as follows:
Conversion:
1.61 km = 1 mile
837 km = X mile.
Cross-multiplying, we have:
[tex]X=\frac{837}{1.61}[/tex]
X = 519.88 miles.
Mathematically, time is given by this formula:
[tex]Time = \frac{distance}{speed}[/tex]
Substituting the given parameters into the formula, we have;
[tex]Time = \frac{519.88}{75}[/tex]
Time = 6.93 ≈ 7 hours.
Read more on time here: https://brainly.com/question/12199398
4. Consider the following reaction:
A student performs a neutralization reaction at 298 K according to the following reaction:
NaHCO3 (8) + HCH,O2 (aq) → H20 (1) + CO2 (g) + NaC,H3O2 (aq)
The student adds 1.85 g of solid NaHCO3 into a flask containing 75.0 mL of 0.90 M HCH:02. The student
observes the formation of gas bubbles and also that the flask gets cooler to the touch as the reaction proceeds.
Considering all of the students observations that the student made, is the reaction thermodynamically favorable
at all temperatures, no temperatures, high temperatures or low temperatures. Justify (explain) your selection in
terms of AG
Answer:
High temperatures
Explanation:
NaHCO₃ (8) + HCH,O₂ (aq) → H₂O (l) + CO₂ (g) + NaC,H₃O₂ (aq)
As the flask gets cooler to the touch as the reaction proceeds, the reaction is endothermic. This means that ΔH is positive (ΔH>0).
As a gas is formed (bubbles are formed), ΔS is positive (ΔS>0).
In terms of ΔG:
ΔG = ΔH - TΔSIn order for the reaction to be thermodynamically favorable, ΔH has to be negative, thus:
The reaction is favorable if TΔS > ΔH.The greater the temperature, the easier it would be for TΔS to be greater than ΔH.
List a couple general characteristics of primary consumers and list a few examples.
Which type of solution below has a cloudy appearance? (Choose all that apply)
a. Colloids
b. Suspensions
c. Solutions
d. Alloys
The type of solutions which are appearing cloudy are called colloids. Therefore, option a is correct.
What are colloids ?Colloids are mixtures in which particles of one substance are evenly dispersed throughout another substance, creating a stable mixture. The particles in a colloid are larger than those found in a solution, but smaller than those found in a suspension.
Colloids can be found in various states of matter, including solid, liquid, and gas, and they can be formed from a wide range of substances, such as polymers, metals, and biological molecules.
One important characteristic of colloids is their ability to scatter light. This phenomenon, known as the Tyndall effect, occurs when light passes through a colloid and is reflected by the particles, causing the mixture to appear cloudy or hazy.
Colloids also exhibit unique properties related to their size and shape, such as viscosity, surface tension, and Brownian motion. They appear cloudy in nature.
Find more on colloids:
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How many mL of 14.5M lithium carbonate solution must be used to deliver 4.20 g of lithium ion
Answer:
. 750 M
Explanation:
2. Which of the following could the flame test be used for?
plz need help right away !
Explanation:
1 mole = 6.02 x 10^23 atoms (Avogadro’s number)
Step 1) Determine how many grams of a substance are in the problem
Step 2) Find the amount of grams in 1 mole of the substance
3) Multiply step one by step two
What is the mole percent of ethanol (C2H5OH), which consists of 71.0 g of ethanol for every 18.6 g of water present?A. 87.7%.B. 22.1%.C. 26.5%.D. 73.5%.E. 71.0%.
Answer:
Mole percent of Ethanol = 0.5986 * 100 = 59.86%
Explanation:
Mole percent is the percentage of the total moles that is of a particular component.
We have to covert the ethanol and water to moles. This is given by the equation;
Number of moles = Mass / Molar mass
Ethanol;
Number of moles = 71 / 46.07 = 1.5411 mol
Water;
Number of moles = 18.6 / 18 = 1.033 mol
Total mol = 1.5411 mol + 1.033 mol = 2.5741 mol
Mole percent of Ethanol = Number of moles /(Ethanol) / Total moles * 100
Mole percent of Ethanol = 1.5411 mol / 2.5741 mol * 100
Mole percent of Ethanol = 0.5986 * 100 = 59.86%
The theory of evolution states
Answer:
the theory of evolution states that all living things which exist today, and many more that are now extinct, evolved from simple life forms which first developed 3 billion years ago.
Explanation:
2KMnO4 + 16HCl -> 5Cl2 + 2KCl + 2MnCl2 + 8H2O If 6.0 moles of KCl are produced, how many moles of HCl were reacted?
Answer:
Explanation:
You just use the balance mole numbers from the equation.
moles HCl needed/16 from the balanced equation ==> 6KCl/2 from equation
x / 16 = 6/2 Multiply both sides by 16
x = 16 * 6 / 2
x = 48
You need 48 mols of HCl
Which of the following is true regarding the difference between velocity and speed? *
Velocity can be negative whereas speed can only be positive.
Velocity includes a direction whereas speed is a numerical value only.
Velocity relies on displacement whereas speed relies on distance.
All of the above.
Answer:
All of the aboveSpeed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement. Put another way, speed is a scalar value, while velocity is a vector.
Explanation:
Hope it is helpful.....
What is the vapor pressure of a solution in which the mole fraction of the solute is 0.200 and the vapor pressure of the pure solvent is 100.0 torr? (Assume a single nonvolatile, nonelectrolyte solute).
a. 0 torr
b. 80.0 torr
c. 100.0 torr
d. 120.0 torr
e. 20.0 torr
Answer: The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]
where,
[tex]p^0[/tex]= vapor pressure of pure solvent = 100.0 torr
[tex]p_s[/tex] = vapor pressure of solution = ?
i = Van'T Hoff factor = 1 for nonvolatile, nonelectrolyte solute
[tex]x_2[/tex] = mole fraction of solute = 0.200
[tex]\frac{100.0-p_s}{100.0}=1\times 0.200[/tex]
[tex]p_s=80.0torr[/tex]
The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr
Some instruments differentiate individual quanta of electromagnetic radiation based on their energies. assume such an instrument has been adjusted to detect quanta that have 3.50× 10–16 j of energy. what is the wavelength of the detected radiation? give your answer in nanometers.
Answer:
5.68×10¯¹⁰ m
Explanation:
From the question given above, the following data were obtained:
Energy (E) = 3.50×10¯¹⁶ J
Wavelength (λ) =?
Energy (E) and wavelength (λ) are related according to the following formula:
E = hv/λ
Where
E => is the energy
h => is the Planck's constant
v => is the velocity of electromagnetic radiation
λ => is the wavelength of the radiation.
With the above formula, we can obtain the wavelength of the radiation as follow:
Energy (E) = 3.50×10¯¹⁶ J
Planck's constant (h) = 6.63×10¯³⁴ Js
Velocity (v) = 3×10⁸ m/s
Wavelength (λ) =?
E = hv/λ
3.50×10¯¹⁶ = 6.63×10¯³⁴ × 3×10⁸ / λ
3.50×10¯¹⁶ = 1.989×10¯²⁵/ λ
Cross multiply
3.50×10¯¹⁶ × λ = 1.989×10¯²⁵
Divide both side by 3.50×10¯¹⁶
λ = 1.989×10¯²⁵ / 3.50×10¯¹⁶
λ = 5.68×10¯¹⁰ m
Thus, the wavelength of the radiation is
5.68×10¯¹⁰ m
How to set up the rate expressions for the following mechanism?
A → B k1
B → A k2
B+C → D k3
If the concentration of B is small compared with the concentrations of A, C, and D, the steady-state approximation may be used to derive the rate law. Derive the rate law, and show that this reaction may follow the first-order equation at high pressures and the second-order equation at low pressures.
Answer:
Explanation:
From the given information:
A → B k₁
B → A k₂
B + C → D k₃
The rate law = [tex]\dfrac{d[D]}{dt}=k_3[B][C] --- (1)[/tex]
[tex]\dfrac{d[B]}{dt}=k[A] -k_2[B] -k_3[B][C][/tex]
Using steady-state approximation;
[tex]\dfrac{d[B]}{dt}=0[/tex]
[tex]k_1[A]-k_2[B]-k_3[B][C] = 0[/tex]
[tex][B] = \dfrac{k_1[A]}{k_2+k_3[C]}[/tex]
From equation (1), we have:
[tex]\mathbf{\dfrac{d[D]}{dt}= \dfrac{k_3k_1[A][C]}{k_2+k_3[C]}}[/tex]
when the pressure is high;
k₂ << k₃[C]
[tex]\dfrac{d[D]}{dt} = \dfrac{k_3k_1[A][C]}{k_3[C]}= k_1A \ \ \text{first order}[/tex]
k₂ >> k₃[C]
[tex]\dfrac{d[D]}{dt} = \dfrac{k_3k_1[A][C]}{k_2}= \dfrac{k_1k_3}{k_2}[A][C] \ \ \text{second order}[/tex]
The point where ground water reaches the surface and pours out is called a summer? true or false
Answer:
False
Explanation:
Groundwater and surface water have a relationship.
Groundwater is the water that is contained in a subsurface layer of an underlying soil/rock whereas surface water is that found in a lake, river or some other surface cavities.
However, when groundwater is discharged to surface water bodies, it is said to be surface water. Thus the statement asked is false.
Which of the following devices function on redox reaction ... Drycell, car battery and electric generator
Answer:
Drycell and car battery
Explanation:
Is it only one answer because I think both of these are redox reactions.
From previous experiments, this chemical reaction is known to absorb of energy. The position of the piston is monitored, and it is determined from this data that the system does of work on the piston during the reaction. Is the reaction exothermic or endothermic? exothermic endothermic Does the temperature of the water bath go up or down? up
Hello. Your question is missing data, which makes it difficult to answer it with exactness, but I will try to help you in the best possible way.
If the reaction absorbs energy it means that the reaction is endothermic. This is because endortemic reactions are those that absorb energy from the environment, as opposed to exothermic reactions that release energy into the environment.
In that case, if the reaction is absorbing energy, it is appropriate for the water bath temperature to drop.
A gas has a pressure of 0.0370 atm at 50.0°C. What is the pressure at 0.00°C?
How many mL of 14.5M lithium carbonate solution must be used to deliver 4.20 g of lithium ion
Answer:
10.3 g Li) / (6.9410 g Li/mol) x (1 mol Li3PO4 / 3 mol Li) / (0.750 mol/L Li3PO4) = 0.6595 L = 660. mL
Explanation: