Answer:
109°
Explanation:
According to Valence Shell Electron Pair Repulsion Theory, electron pairs on the valence shell of the central atom of a molecule must be positioned as far apart in space as possible to minimize repulsion between valence shell electron pairs.
The shape of a molecule depends on the number and type of electron pairs on the valence shell of its central atom. Lone pairs generally cause more repulsion than bond pairs of electrons.
The ideal bond angle for a molecule with four bonds is 109° which corresponds to a tetrahedral geometry. This enables the four bonds to spread as far apart in space as possible.
You have 723 ml of 3.99 M HCl. Using a volumetric pipet, you take 326 ml of that solution and dilute it to 976 ml in a volumetric flask. Now you take 100.00 ml of that solution and dilute it to 119 ml in a volumetric flask. What is the concentration of hydrochloric acid in the final solution
Answer:
1.12M
Explanation:
The initial concentration of the HCl solution is 3.99M. You are doing 2 dilutions:
In the first you take 326mL and dilute the solution to 976mL; that means you are diluting the solution:
976mL / 326mL = 2.99 times.
The concentration of this solution is:
3.99M / 2.99 = 1.33M
Now, in the second dilution, you take 100mL of the diluted solution and dilute it to 119mL. The concentration of this final solution is:
119mL / 100mL = 1.19 times.
1.33M / 1.19 =
1.12MThe final concentration of hydrochloric acid present is 1.11 M.
In the first dilution;M1V1 = M2V2
M2 = 3.99 M × 326 ml/976 ml
M2 = 1.33 M
In the second dilution:
M1V1 = M2V2
M2 = 1.33 M × 100.00 ml/119 ml
M2 = 1.11 M
Hence, the final concentration of hydrochloric acid present is 1.11 M.
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Please help asap!! Need help for problem #2.
Naturally occuring iron, contains 5.82% ^54Fe, 91.66% ^56Fe, 2.19% ^57Fe, and 0.33% ^58Fe. The reslective atomic masses are 53.940 amu, 55.935 amu, 56.935 amu and 57.933 amu. Calculate the average atmoic mass of iron. (show work)
Answer:
55.56 amu
Explanation:
Let A, B, C and D represent the four isotopes of iron.
The following data were obtained from the question:
Isotope A (Fe-54):
Mass of A = 53.940 amu
Abundance (A%) = 5.82%
Isotope B (Fe-56):
Mass of B = 55.935 amu
Abundance (B%) = 91.66%
Isotope C (Fe-57):
Mass of C = 56.935 amu
Abundance (C%) = 2.19%
Isotope D (Fe-58):
Mass of D = 57.933 amu
Abundance (D%) = 0.33%
Average atomic mass =.?
The average atomic mass of the iron can obtained as follow:
Average atomic mass = [(mass of A × A%)/100] + [(mass of B × B%)/100] + [(mass of C × C%)/100] + [(mass of D × D%)/100]
Average atomic mass = [(53.940 × 5.82)/100] + [(55.935 × 91.66 )/100] + [(56.935 × 2.19)/100] + [(57.933 × 0.33)/100]
= 2.848 + 51.270 + 1.247 + 0.191
= 55.56 amu
Therefore, the average atomic mass of the iron is 55.56 amu
Part Of flowers that contains pollen is
Please answer right
Answer:
its the stamen, it also supports the Anther.
Answer:
The Stamen
Explanation:
The stamen is a slender filament supporting the anther, it is what produces and holds pollen in flowers.
Consider this aqueous reaction.
HNO3(aq) + Ba(OH),(aq)
What is the formula for the salt that forms?
Answer:
Ba(NO3)2 barium nitrate
Explanation:
2HNO3+Ba(OH)2=Ba(NO3)2+2H2O
acid base salt water
Which ocean zone lies inside V-shaped ocean trenches? O A. Bathypelagic O B. Abyssopelagic Ο Ο Ο Ο O C. Mesopelagic O D. Hadalpelagic
Answer:
O D. Hadalpelagic is the answer.
HELP 100 POINTS WILL MARK BRAINLIEST In ancient times, early astronomers watched stars travel across the sky in one direction for several months, then over the course of a few weeks the stars would reverse course and move in the opposite direction. After these few weeks, the stars would reverse direction again and resume their original course. The ancient astronomers called these “wanderer stars”. After more research was done, it was found that these “wanderer stars” were actually other planets. As more data was collected, it was shown that all planets move at different speeds as they travel in their orbits around the Sun. As the Earth moves in its orbit, it moves faster than some planets and slower than others. This causes the Earth to “pass” some planets as it travels, which results in the appearance that the other planets move backwards. Is this a description of a scientific law or scientific theory? 100 points PLEASE HELP
Which option gives an object's volume in SF units?
O
A. 4.3 kg
B. 2.6 m3
C. 5.5 K
D, 3.4L
SUBMIT
Answer:
The correct answer is:
2.6 m3 (B)
Explanation:
SF unit stands for Stowage factor unit. Stowage factor is the volume occupied by one unit of mass (weight) when stowed in cargo space. SF expresses the unit in cubic meters (m³) or cubic feet. SF is a unit of measurement that indicates how much space (volume) a particular unit of cargo occupies in a ship's cargo compartment
Making a Lis changing something to improve your work. A) scenario
B) revision
C) entry event
D) wish list
The measure of the amount of matter is known as _______?
Answer:
Mass is a measure of the amount of matter in a substance or an object. The basic SI unit for mass is the kilogram (kg), but smaller masses may be measured in grams (g).
the study of Mixture
Answer:
Mixtures can be either homogeneous or heterogeneous. A mixture in which its constituents are distributed uniformly is called homogeneous mixture, such as salt in water. A mixture in which its constituents are not distributed uniformly is called heterogeneous mixture, such as sand in water.
Explanation:
Which statement correctly defines pasteurization?
Answer:
Pasteurization is the process by which liquids are heated to kill bacteria that may be present.
explanation I got the correct answer
Answer:
Pasteurization is the process by which liquids are heated to kill bacteria that may be present.
Explanation:
i just did that one
Which of the following is true for all chemical reactions? The total mass of the reactants increase. The total mass of the products is greater than the total mass of the reactants. The total mass of the products is less than the total mass of the reactants. The total mass of the reactants equals the total mass of the products.
Answer:
The total mass of the reactants equals the total mass of the products.
Explanation:
The true statement for all chemical reactions is that the total mass of the reactants equals the total mass of the products.
What is chemical reaction?Chemical reactions are those reactions in which reactants react with each other and converted into products for the completion of the reaction.
Let us assume a chemical reaction:
A + B → C + D
Where, A & B are reactants which are converted into products C & D. Means mass of reactants will convert into the mass of products as it follows the law of conservation of mass.
So, total mass of the reactants equals the total mass of the products.
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can two different elements have the same atomic symbol
Answer:
No.
Explanation:
They all are in sync.
Ex. 1 Hydrogen, 2 Helium, etc.
two things we can learn from fossils.
Answer:
fossils come from way back they can be left from dinosaurs and other species
Explanation:
Answer:
Using fossils, you can learn about extinct animals and plants, that's one. Two, you can learn about evolutionary traits and the fact that evolution exists.
Explanation:
Enter the full electron configuration for S2�. What is the atomic symbol for the noble gas that also has this electron configuration?
Answer:
1. Electronic configuration of sulphide ion S²¯ (18) => 1s² 2s²2p⁶ 3s²3p⁶
2. Ar
Explanation:
1. S²¯ simply indicates that the sulphur atom (S) has gained two extra electrons.
Thus we shall write electron configuration of sulphur (S) and sulphide ion (S²¯) as follow:
The electronic configuration of S²¯
S (16) => 1s² 2s²2p⁶ 3s²3p⁴
S²¯ (18) => 1s² 2s²2p⁶ 3s²3p⁶
2. Determination of the noble gas element that has the same electronic configuration as S²¯.
This is illustrated below:
Sulphur (S) has 16 electrons while the sulphide ion (S²¯) has extra 2 electrons making it to have a total electron of 18. Observing the elements in the periodic table, only Argon has 18 electrons with electronic configuration as:
Ar (18) => 1s² 2s²2p⁶ 3s²3p⁶
Therefore, sulphide ion (S²¯) has the same electronic configuration as Argon (Ar).
Which of the following are observations? Select all that apply.
A. Watching table salt dissolve in waters'
B. Feeling the sensation of ice held in the hand.
C. Smelling ammonia used in a cleaning solution.
D. Hearing a loud bang when a balloon filled with hydrogen gas is ignited.
E. Looking at the readout of a digital scale when measuring reagents for an experiment.
Answer:
A and E
Explanation:
Observing means looking or watching with the eyes etc..
Observation is the component of research and involves inspection of the hypothesis. Dissolving table salt and reading a digital scale is an example of observation. Thus, options A and E are correct.
What is an observation?Observation is that the component of the experimental style that defines observance or the review of the activity that underwent sure conditions.
It will be seen as a press release supported hearing, vision, etc. The dissolving of the flavorer is associate degree noticeable task wherever one will see the salt gets dissolved within the water to create a combination.
Similarly, the digital scales are used to measure the substances and use a readouts to estimate the quantity of the reagents to be used by directly seeing on the digital screen of the machine.
Therefore, dissolving salt and digital scale is observable.Hence options A and E are correct.
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Which is most reactive toward electrophilic aromatic substitution?
Complete Question
Which is most reactive toward electrophilic aromatic substitution?
A Phenol
B Anisole
C Nitro-benzene
D Benzene
Answer:
The correct option is A
Explanation:
Generally the rate at which electrophilic aromatic substitution reaction occur is dependent on the nucleophilicity(nucleophile strength ) of Benzene ring.Now a functional group which increase the electron density in the benzene ring when attached to it increases its nucleophilicity and this in-turn will increase the rate at which electrophilic aromatic substitution reaction occur
Now Phenol is a compound that is made up of OH functional group and then the benzene ring
Anisole is a compound that is made up of [tex]OCH_3[/tex] functional group and then the benzene ring
Nitro-benzene is a compound that is made up of [tex]NO_2[/tex] functional group and then the benzene ring
Now since OH is the highest In series of activating group compared to the activation groups we are considering (i.e [tex]OCH_3[/tex] and [tex]NO_2[/tex] )
Then Phenol is the answer
How many significant figures are in the following numbers?
a. 0.002849
b. 40030
Which phrase best describes the outer planets?
rocky with few moons
gaseous with slow rotations
dense with few moons
gaseous with low density
Answer: D. Gaseous with low density
Explanation: Took the test :)
Answer:
gaseous with low density
Explanation:
how many atoms are in 2 miles of h2o
Answer:
one mole of water contains 6.02 x 1023 MOLECULES of water.
But each molecule of water contains 2 H and 1 O atom = 3 atoms, so there are approximately 1.8 x 1024 atoms in a mole of water.
Explanation:
hope it helps you paigegeorge
What happens to the principle energy level number when moving from s to p sub levels
Answer:
The principal energy level remains the same
Explanation:
A principal energy level is one defines where electrons reside in an atom and that can contain one or more sub levels and have 2·n² number of electrons located in different sub levels within the energy level. Therefore, when moving up from s to p within the same principal energy level, the principal energy level does not change value.
3. Calculate each of the following:
a) kg of 4.6x1021 molecules of nitrogen dioxide
b) moles of chlorine atoms in 0.615 g of C2H4Cl2
c) number of hydride ions in 5.82 g of strontium hydride
Answer:
the answers are at the very bottom of each picture
Explanation:
i really hope this helps you:)
Give two examples of rocks composed of only one material.
Answer:
pyroxenite, quartzite, dunite (over 90% olivine), anorthosite (over 90% plagioclase feldspar), marble, chalk, gypsum
Explanation:
What is a nebula? ...........................
a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
a clouded spot on the cornea causing defective vision.
Hope this helped
Answer:
A cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
Explanation:
1) Chemistry is a (physical/biological) science?
Answer:
Explanation:
Biological.
I hope I helped you! :)
What is the charge of a chromium ion that has lost 4 electrons?
Answer:
+2.
Explanation:
Hello,
In this case, since chromium has six valence electrons in its outer shell, when it loses four electrons it remains with two of them, therefore it charge as chromium ion is +2, so it is written as Cr⁺² and named as chormium (II) or hypochromous ion.
Best regards.
Consider a closed container of gas that is a mixture of 30% CO2 and 70% N2 at room temperature 20°C. The gases are in thermal equilibrium with one another. a) Which has the higher kinetic energy, the average CO2 or N2 molecule? b) What is that root-mean-square velocity of a CO2 molecule? For reference, a carbon atom has 6 protons, a nitrogen atom has 7 protons, and an oxygen atom has 8 protons.
Answer:
a. the kinetic energy will be the same.
b. [tex]\mathbf{\overline v = 407.65 \ m/s}[/tex]
Explanation:
The kinetic theory deals with how the arrangement of particles of a substance determines the properties that substance will possess and the state in which it is likely to be found under a given set of conditions. From the postulates of the kinetic theory of gases, The average kinetic energy of the gas molecules is a measure of the temperature of the gas molecules, This implies that the kinetic energy is dependent on the temperature.
i.e
[tex]K.E = \dfrac{3}{2} \ KT[/tex]
where ;
K = Boltzmann Constant
Since the given gases are in thermal equilibrium, therefore, the kinetic energy will be the same.
b).
The root mean square velocity of CO2 molecule is represented by the equation :
[tex]\overline v = \sqrt{\dfrac{3RT}{M_m}}[/tex]
[tex]\overline v = \sqrt{\dfrac{3\times 8.314 \ J/K /mole \times (293.15 \ K ) }{44 \times 10^{-3} \ kg / mol}}[/tex]
[tex]\overline v = \sqrt{\dfrac{7311.7473 }{44 \times 10^{-3} }}[/tex]
[tex]\overline v = \sqrt{166176.075 \ m/s}[/tex]
[tex]\mathbf{\overline v = 407.65 \ m/s}[/tex]
2. Chemical changes often cannot be reversed because they
produce new chemical substances.
TRUE
FALSE
Answer:
True
Explanation:
Answer:
True...
I’ve tooken a test like that before
An aluminum cylinder has a radius of 3.2 cm and a length of 8.6 cm. What is the mass of the aluminum cylinder if aluminum has a density of 2.7 g/cm3?
please help :)
Answer:
750g of Aluminum
Assuming 8.6 cm lenth is the height of the cylinder. The volume of a cylinder is: V = [tex]\pi[/tex]*r^2*h
V = 3.14cm x 10.24cm x 3.6cm
V = 280cm^3
Now density = mass/volume
2.7g/cm^3 = mass/280cm^3
2.7g/cm^3 x 280cm^3 = mass/280cm^3 x 280cm^3
= 750g of Aluminum
What are the steps to solving: 0.8102m x 3.44m
Answer:
2.787088m^2
Explanation:
well you multiply both numbers and then since its multiplication you can add both variables and there two
The steps for solving: 0.8102m x 3.44m is given below in explanation part, and the answer for this is [tex]2.788088m^2[/tex].
To begin solving the 0.8102m multiplied by 3.44m multiplication issue, multiply the numerical numbers together: 0.8102 x 3.44 = 2.788088.
Then add the units together: m x m = [tex]m^2[/tex]. Finally, add the numerical value and unit to get the following result: 2.788088 [tex]m^2[/tex].
We are multiplying two measures by metres (m) in this computation. When we multiply the numerical values, we get the product, and when we multiply the units, we get the final unit, which in this case is metres squared ( [tex]m^2[/tex]).
Thus, this signifies that the multiplication reflects a computation of area. The final value, 2.788088 [tex]m^2[/tex], is the product of multiplying the two measures supplied.
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