Answer:
Electromagnetic spectrum
Explanation:
Telescopes are used by observers to monitor various electromagnetic radiation. Only one component of the visible radiation can be observed by each type of instrument. Telescopes, ultraviolet telescopes, optical celestial objects, and other types of telescopes are available.
how many mols of Ti is 3.15 * 10^23 atoms of Titanium
Answer: There are 0.523 moles of Titanium in [tex]3.15\times 10^{23}[/tex] atoms of Titanium
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]
[tex]\text{Number of moles of Titanium}=\frac{3.15\times 10^{23}}{6.023\times 10^{23}}=0.523moles[/tex]
Which of the following is true about the efficiency of energy transfer in an ecosystem?
a The more energy the organism requires, the more efficient the energy transfer.
b. All energy transfers have the same efficiencies.
C. The less energy the organism requires, the more efficient the energy transfer.
d. The most efficient energy transfers are in large, warm-blooded animals.
Please select the best answer from the choices provided
A
B
ОООО
C
D
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Answer:
C. The less energy the organism requires, the more efficient the energy transfer.
Answer:
C
Explanation:
Trust the process
Edge 2021
Na + - FeCl, - _NaCl + Fe
NO LINKS!!!!
Answer:
2Na + FeCl2 → 2NaCl + Fe (sodium)
Explanation:
ANSWERED
Graph the number of A particles versus the time and the number of B particles versus the time. Plot both data sets on the same graph.
How many moles of Na are in 42g of Na?
Answer:
n=m/M, so
Explanation:
Molar mass of Na is 22,9... so rounded to 23
n=42g/23g/mol
=1,826mol
Give a reason for each of the following laboratory practices:
I. KMnO4 solution is not acidified with HNO3 before titration
II.FeSO4 solution is usually prepared fresh when needed
III. Alkali are not stored in glass stoped reagent bottles
Answer:
See explanation
Explanation:
The acid commonly used to acidify KMnO4 is H2SO4. The reason why HNO3 is not used is because HNO3 is itself a strong oxidizing agent. HCl is not used because it can react with KMnO4.
FeSO4 solution is usually prepared fresh when needed because if the solution is prepared and left to stand for sometime, FeSO4 is oxidized to Fe2(SO4)3 by air. Fe III does not give the brown ring test.
Alkali are not stored in glass stopped reagent bottles because very strong alkali can cause the stopper to corrode and fuse to the neck of the bottle making it very difficult to open the reagent bottle.
85% of what number is 17? EXPLAIN
Answer:
85% of 20 is 17
Explanation:
You can multiply 85% and 20 or subtract 85% from 20.
What are the correct coefficients for the following chemical reaction:
Al +
Br2 --> __AlBr3
O 3, 3,2
O 2,3,2
0 2,2,3
O 3,2,2
Answer:
2Al + 3Br2 = 2AlBr3 so the second option is right
Platinum is less reactive than tin. Suggest why steel cans are coated with tin rather than platinum.
Explanation:
Food cans are coated with tin and not with zinc because zinc is above the tin in reactivity series means more reactive than tin and can react with food elements preserved in it.
Which of the following statements apply to the general experimental procedure for determining the heat of reaction as described in the experiment reading? One or more may be correct and you will receive negative points for incorrect answers.
A. Measurements of the temperature of the solution in the calorimeter should be taken at regular intervals for several minutes before the reactant is added.
B. The solution in the calorimeter should not be stired during the experiment because stirring wil slow the reaction
C. The solution calorimeter does not need to be rinsed or dried between runs because the reaction solutions are all aqueous.
D. Temperature readings need to be taken at regular intervals after the highest temperature reading is observed to determine the rate of heat loss from the calorimeter.
Answer:
The following statements apply to the general experimental procedure for determining the heat of reaction:
A. Measurements of the temperature of the solution in the calorimeter should be taken at regular intervals for several minutes before the reactant is added.
B. The solution in the calorimeter should not be stirred during the experiment because stirring will slow the reaction
D. Temperature readings need to be taken at regular intervals after the highest temperature reading is observed to determine the rate of heat loss from the calorimeter.
Explanation:
Number of atoms of C in 14 moles of C4H10 are:
5.81x10^23
24.09x10^23
84.31x10^23
337.23x10^23
Hhelllp mee faastttt! Pls
What I know about the Alveoli and Gas exchange
Explanation:
What happens during gas exchange in the alveoli?
These are called alveoli. They inflate when a person inhales and deflate when a person exhales. During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs.
What is the role of alveoli in gas exchange?
The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.
For a particular reaction at 135.4 °C, Δ=−775.41 kJ/mol, and Δ=817.91 J/(mol⋅K).
Calculate ΔG for this reaction at 12.7 °C.
Δ=
Answer:
[tex]-675.053\ \text{kJ/mol}[/tex]
Explanation:
[tex]\Delta G[/tex] = Gibbs free energy = [tex]-775.41\ \text{kJ/mol}[/tex]
[tex]\Delta S[/tex] = Change in entropy = [tex]817.91\ \text{J/mol K}=0.81791\ \text{kJ/mol K}[/tex]
[tex]T[/tex] = Temperature = [tex]135.4^{\circ}\text{C}=408.55\ \text{K}[/tex]
[tex]\Delta H[/tex] = Change in enthalpy
Gibbs free energy is given by
[tex]\Delta G=\Delta H-T\Delta S\\\Rightarrow \Delta H=\Delta G+T\Delta S\\\Rightarrow \Delta H=-775.41+408.55\times 0.81791\\\Rightarrow \Delta H=-441.253\ \text{kJ/mol}[/tex]
[tex]T=12.7^{\circ}\text{C}=285.85\ \text{K}[/tex]
[tex]\Delta G=\Delta H-T\Delta S\\\Rightarrow \Delta G=-441.253-285.85\times 0.81791\\\Rightarrow \Delta G=-675.053\ \text{kJ/mol}[/tex]
The required Gibbs free energy is [tex]-675.053\ \text{kJ/mol}[/tex].
How many molecules of CO2 are present in 0.6642 moles of CO2?
Answer:
1* 6.022*10^23=6.022*10^23 molecules of CO2 are present.
A gas occupies a volume of 140 mL at 35.0°C and 697 mm Hg. What is the volume of the gas at STP?
Answer:
113.80 mL
Explanation:
Given that:
Volume [tex]V_1 = 140 mL[/tex]
Temperature [tex]T_1 = 35.0^0C[/tex]
[tex]= (273 + 35) = 308 \ K[/tex]
Pressure [tex]P_1 = 697 mmHg[/tex]
At standard temperature and pressure;
Temperature [tex]T_2 = 273 K[/tex]
Pressure[tex]P_2[/tex] = 760 mmHg
Using the formula for a combined gas law:
[tex]\dfrac{P_1V_1}{T_1} = \dfrac{P_2V_2}{T_2}[/tex]
[tex]V_2 = \dfrac{P_1V_1T_2}{T_1P_2}[/tex]
[tex]V_2 = \dfrac{697 \ mmHg \times 140 \ mL \times 273 \ K }{308 \ K \times 760 \ mmHg}[/tex]
[tex]\mathbf{V_2 = 113.80 \ mL}[/tex]
i) __________are rigid due to strong (ii)___________ of attraction between the particles
Answer:
Liquid Solids are rigid due to strong glass of attraction between the particles.
Explanation:
Which of these metals will displace Iron from Iron Oxide ?
-Copper
-Magnesium
-Silver
-Tin
Answer:
Magnesium
Explanation:
Magnesium is above iron in the reactivity series, which means that Mg can take oxygen from iron as it is a more reactive metal.
7
What is the name of this isotope?
Periodic Table link
P: 36
N: 48
Answer:
Because the number of neutrons is different, the mass number is different. Isotopes are written in two different ways. They can be written using their symbol with the mass number (to the upper left) and atomic number (to the lower left) or the isotope name is written with a dash and the mass number
Explanation:
I don't know the answer but I am sure this will help you out.
Which type of bonding is present when valence electrons move within the sample?
A. metallic bonding
B. hydrogen bonding
C. covalent bonding
D. ionic bonding
Answer:
Metallic bonding.....
Problems 307 How many milliliters of a 2.5 M NaCl solution would be needed to prepare each solution? a. 1.5L of a 0.75m solution
Answer:
450 mL
Explanation:
First we calculate how many NaCl moles would there be in 1.5 L of a 0.75 M solution, using the definition of molarity:
Molarity = moles / LitersMoles = Molarity * LitersMoles = 1.5 L * 0.75 M =1.125 molOnce again using the definition of molarity, we now calculate how many liters of a 2.5 M solution would have 1.125 moles:
Liters = 1.125 mol / 2.5 M = 0.45 LFinally we convert 0.45 liters to mL:
0.45 L * 1000 = 450 mLA cylinder, with a piston pressing down with a constant pressure, is filled with 1.90 moles of a gas (n1),
and its volume is 40.0 L (V1). If 0.400 mole of gas leak out, and the pressure and temperature remain the
same, what is the final volume of the gas inside the cylinder?
Answer:
31.58 L
Explanation:
From the question given above, the following data were obtained:
Initial mole (n₁) of gas = 1.90 moles
Initial volume (V₁) = 40 L
Final mole (n₂) = 1.90 – 0.40 = 1.5 moles
Final volume (V₂) =.?
The final volume of the gas can be obtained as follow;
V₁ / n₁ = V₂ / n₂
40 / 1.9 = V₂ / 1.5
Cross multiply
1.9 × V₂ = 40 × 1.5
1.9 × V₂ = 60
Divide both side by 1.9
V₂ = 60 / 1.9
V₂ = 31.58 L
Thus, the final volume of the gas is 31.58 L
What does the phrase gravitational pull mean as it is used in the text?
Because meteors are so small, they often get pulled into planetary orbits, while asteroids and comets are large enough that they stay within the gravitational pull of the sun.
1. A force that pushes one thing away from another
2. Something that makes an object stay on the ground
3. Something that pulls an object strongly downward
4. The force of one thing pulling another thing closer
what is the double bond of XeF4
What is a solvent ?
Answer:
A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid.
Explanation:
What is the value of Q when 100.0 mL of a 7.6 10-4 M Mg(NO3)2 is added to 100.0 mL of 7.1 10-4 M NaOH? (Ksp for Mg(OH)2 = 8.9 ✕ 10-12)
Answer:
Q = 4.8x10⁻¹¹
Explanation:
The solubility of Mg(OH)₂ is:
Mg(OH)₂(s) → Mg²⁺(aq) + 2OH⁻(aq)
And Ksp is:
Ksp = [Mg²⁺] [OH⁻]²
Where [] are concentrations in equilibrium
Thus, Q could be defined as:
Q = = [Mg²⁺] [OH⁻]²
Where [] are actual concentrations
[Mg(NO₃)₂] = [Mg²⁺]
And [NaOH] = [OH⁻]
Both solutions are diluted twice (Because 100mL of each solution are diluted to 200mL). The equilibrium concentrations are:
[Mg²⁺] = 7.6x10⁻⁴M / 2 = 3.8x10⁻⁴M
[OH⁻] = 7.1x10⁻⁴ / 2 = 3.55x10⁻⁴M
That means Q is:
Q = [3.8x10⁻⁴M] [3.55x10⁻⁴M]²
Q = 4.8x10⁻¹¹
An aluminum pan and a copper pan have the same mass and are heated to the same temperature. Which will feel hotter?
Answer:
The copper pan!
Explanation:
Copper conducts heat well because its atoms contain only one free valence electrons in the outer shell. Elements with a low number of valence electrons transfer heat the best, and copper has only one. Valence electrons move about freely.
Good luck on your assignment!
Which describes the polarity in a water molecule?
A. partial negative charge on the oxygen atom because its electrons are pulled toward the hydrogen atoms
B. partial negative charge on the oxygen atom because it pulls electrons from the hydrogen atoms
C. partial positive charge on the oxygen atom because it pulls electrons from the hydrogen atoms
D. partial positive charge on the oxygen atom because its electrons are pulled toward the hydrogen atoms
The answer is B
Answer:
B. partial negative charge on the oxygen atom because it pulls electrons from the hydrogen atoms
Explanation:
Oxygen has a charge of 6 so they need to pull 2 electrons from hydrogen, which creates a partial negative charge.
Cells are the basic unit of structure and function in living
things. True or false
Answer:
This statement is true
Jeff wants to record the diameter of a long, thin wire using an instrument. Which of the following instruments should be use? A Altimeter B Microscope c Measuring scale D.Micrometer
Answer:
D
Explanation:
5. What is the Moh's hardness scale? Can a mineral with a
hardness of 3 scratch a mineral with a hardness of 5?