Answer:
c. 2 and 3 only
Explanation:
When you compact the bag of trash you make it smaller, so the volume changes. And the density is the mass divided by the volume, so as the volume changed the density obligatorily change too
Why is the average atomic mass used when calculating grams of a
substance?
A. The average atomic mass is known to more significant figures.
B. The elements in the substance are mixtures of their isotopes.
C. The exact weights of the isotopes are not known.
D. The number of isotopes in the sample is constantly changing.
Answer:
B. The elements in the substance are mixtures of their isotopes.
How long does it take, on average, for one centimetre of soil to form
Which of the following is an oxide which is strongly acidic?
(a) Na2O.
(b) MgO
(c) SiO2.
(d) P2O5.
Answer:
answer of your question is 4th
Explanation:
P205
Now look at the volcano map what type of boundary tends to give rise to volcanic activity
Answer:
Volcanoes occur primarily on convergent boundaries, specifically oceanic-continental convergent boundaries.
Explanation:
plato
Need help.
Sodium Sulphate crystallises out as Na2SO4.10H2O. It is prepared by titration. 25.0cm^3 aquas of NaOH solution having a concentration of 2.24 mol/dm^3 reacted with H2SO4 to give Na2SO4.10H2O. The molecular mass of Na2SO4.10H2O = 322 grams. Find the % yield of Na2SO4.10H2O.
Answer:
Assuming the mass of Na2SO4.10H2O obtained from the crystallization was: 8.5g
The % yield is 94.3%
Explanation:
Assuming the mass of Na2SO4.10H2O was:
Based on the reaction:
2NaOH + H2SO4 + 8H2O →Na2SO4.10H2O
Where 2 moles of NaOH reacts producing 1 mole of Na2SO4.10H2O
To solve this question we need to find the moles of NaOH added. With the moles and the reaction we can find the moles of Na2SO4.10H2O and its actual theoretical yield. Assuming the mass of Na2SO4.10H2O produced was: 8.5g
we can find the percent yield as follows:
Moles NaOH:
25.0cm³ = 0.0250dm³ * (2.24mol/dm³) = 0.056 moles NaOH
Moles Na2SO4.10H2O:
0.056 moles NaOH * (1mol Na2SO4.10H2O / 2mol NaOH) = 0.028 moles Na2SO4.10H2O
Mass Na2SO4.10H2O:
0.028 moles Na2SO4.10H2O * (322g / mol) = 9.016g Na2SO4.10H2O = Theoretical yield
Percent yield is 100 times the ratio between actual yield:
8.5g / 9.016g * 100 = 94.3%
Draw the structure for :
3,3,4-trimethylhex-2-ene
Answer:
answer is in the picture.
Define oxidation in terms of election transfer
Explanation:
Is the loss of electrons, gains of oxygen or loss of hydrogen
Answer:
Oxidation is the loss of electrons or an increase in the oxidation state of an atom, an ion, or of certain atoms in a molecule. Reduction is the gain of electrons or a decrease in the oxidation state of an atom, an ion, or of certain atoms in a molecule
balance the equation .......qn 5.......help
Answer:
MnO4 + 4 H2C2O4 = Mn + 8 CO2 + 4 H2O
ii.
ci
What is the name of the organic compound
Answer.
Hydrocarbons are compounds that contain carbon and hydrogen only
Explanation:
a. c3H4 methane
b.c3H4.propene
c.c5H8
Had beryllium and calcium already been discovered
Answer:
Yes
Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. ... Notable gemstones high in beryllium include beryl (aquamarine, emerald) and chrysoberyl.
Calcium is a mineral that is necessary for life. In addition to building bones and keeping them healthy, calcium enables our blood to clot, our muscles to contract, and our heart to beat. About 99% of the calcium in our bodies is in our bones and teeth.
Rank these solutions from the most alkaline (1) to the least alkaline (5).
phosphorus react with carbon
Answer:
Phosphorus atoms can bond with oxygen atoms to form ester groups. These can bond with carbon atoms, yielding a large number of organic phosphorus chemicals. These are found in many important biological processes
Help me please
The options are
A. Translation
B. Rotation
C. Enlargement
D.reduction
Answer:
C. Enlargement
Explanation:
please help me with this
Answer:
a. B
b. C
c. A
d. A
e. B
f. -266
g. B and D
What is the name of the compound with the formula B2C14?
Answer:
Diboron tetrachloride ---> B2Cl4
what are some of the uses of halogens?
Answer:
Halogens are used in, water and sanitation, plastics, pharmaceutical, pulp and paper, textile, military and oil industries. Bromine, chlorine, fluorine and iodine are chemical intermediates( bleaching agents and disinfectants). Chlorine is used to purify water. Chlorine also is part of salt, sodium chloride, which is one of the most widely used chemical compounds. Fluorine is used in fluorides, which are added to water supplies to prevent tooth decay.
hopes this helps~
Answer:
What are some uses of halogen elements? Chlorine is used to purify water. Chlorine also is part of salt, sodium chloride, which is one of the most widely used chemical compounds. Fluorine is used in fluorides, which are added to water supplies to prevent tooth decay.
Explanation:
Halogen, any of the six nonmetallic elements that constitute Group 17 (Group VIIa) of the periodic table. The halogen elements are fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). They were given the name halogen, from the Greek roots hal- (“salt”) and -gen (“to produce”), because they all produce sodium salts of similar properties, of which sodium chloride—table salt, or halite—is best known.
Because of their great reactivity, the free halogen elements are not found in nature. In combined form, fluorine is the most abundant of the halogens in Earth’s crust. The percentages of the halogens in the igneous rocks of Earth’s crust are 0.06 fluorine, 0.031 chlorine, 0.00016 bromine, and 0.00003 iodine. Astatine and tennessine do not occur in nature, because they consist of only short-lived radioactive isotopes.
two boys balanced steady in a sea-saw game is an example of
Which we events will happen if more H, and t, are added to this reaction
when it is in equilibrium?
A. The rate of the backward reaction will increase
The rates of formation of He and I will increase
0. The rate of the forward reaction will increase
D. The rate of formation of HI will increase
Answer:
its is letter c is your answer
Explanation:
I hope this help
Which of the following elements would have the largest electronegativity value?
O cesium
Olithium
O carbon
O sodium
The acid dissociation constant, Ka, of HSO4- is 1.2 × 10-2. What does the Ka value indicate about this compound?
A.
HSO4- is a weak base.
B.
HSO4- is a strong acid.
C.
HSO4- is a weak acid.
D.
HSO4- is a strong base.
Answer:
The answer is HSO4- is a weak acid which will be C
The acid dissociation constant, ka, of HSO4- indicates that it is a strong acid. Details about acid dissociation constant can be found below.
What is acid dissociation constant?The acid dissociation constant denoted by Ka is the measure of the strength of an acid.
The dissociation constant of an acid is used to identify strong acids from their weak counterparts. Strong acids have high Ka values while weak acids have low Ka values.
According to this question, the Ka of HSO4- is 1.2 × 10-², which is quite high.
Therefore, the dissociation constant, ka, of HSO4- suggests that it is a strong acid.
Learn more about acid dissociation constant at: https://brainly.com/question/4363472
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write electronic configuration of chlorine in its ionic state?
Answer:
1s2 2s2 2p6 3s2 3p6
Explanation:
Chlorine is a groups 17 element. The halogens for ions by accepting one electron to form univalent negative ions.
Since chlorine normally contains seventeen electrons, the chloride ion consists of eighteen electrons.
Hence the electronic configuration of chlorine ion is; 1s2 2s2 2p6 3s2 3p6.
¿Que es bacteria y un virus ?
es para hoy por favor ayúdeme
i) Las bacterias son organismos microscópicos unicelulares que prosperan en diversos entornos. Estos organismos pueden vivir en el suelo, el océano y dentro del intestino humano.
ii) Un virus es un agente infeccioso submicroscópico que se replica solo dentro de las células vivas de un organismo. Los virus infectan todas las formas de vida, desde animales y plantas hasta microorganismos, incluidas bacterias y arqueas.
Determine which elements or compounds are products in the
follow reaction equation:
Answer: D is the answer since it is the product of this equation
Explanation: HOPE I AM RIGHT AND IT HELPS!!!
need more explanation feel free to comment in the comment box
hii pls help me to balance chemical equation
calcium hydroxide + hydrochloric acid ------> calcium chloride + water
Answer:
1 Ca(OH)2 + 2 HCl ---> 1 CaCl2 + 2 H2O
Consider the half reactions below for a chemical reaction.
ZnZn2+ (aq) + 2e
Cu?" (aq) + 2e → Cu(s)
What is the overall equation for this chemical reaction?
Zn(s)+ Cu?* (aq) —>Zn2+ (aq) + Cu(s)
O Zn(s) + Cu2+ (aq) — Cu2+ (aq) + 2e-
O Zn2*(aq) + Cu(s) —> Cu2* (aq) + Zn(s)
O Zn2+ (aq) + 22 —> Cu2(aq) + 2e
Answer:
Option A:
Zn(s) + Cu^(2+) (aq) → Cu(s) + Zn^(2+)(aq)
Explanation:
The half reactions given are:
Zn(s) → Zn^(2+)(aq) + 2e^(-)
Cu^(2+) (aq) + 2e^(-) → Cu(s)
From the given half reactions, we can see that in the first one, Zn undergoes oxidation to produce Zn^(2+).
While in the second half reaction, Cu^(2+) is reduced to Cu.
Thus, for the overall reaction, we will add both half reactions to get;
Zn(s) + Cu^(2+) (aq) + 2e^(-) → Cu(s) + Zn^(2+)(aq) + 2e^(-)
2e^(-) will cancel out to give us;
Zn(s) + Cu^(2+) (aq) → Cu(s) + Zn^(2+)(aq)
Which of the following are true for an element? (i)Atomic number= number of protons + number of electrons (ii)Mass number = number of protons+ number of neutrons (iii)Atomic mass= number of protons= number of neutrons (iv)Atomic number = number of protons = number of electrons
Answer:
ii and iv
Explanation:
atomic mass is the sum of protons and neutrons
protons ( postively charged) usually have the same number like electrons( negatively charged)
Which of the following materials is acidic?
A.lemon juice
B.a baking soda solution
C.drain cleaner
D.milk of magnesia
Answer:
lemon juice............
How many moles of electrons is required to deposit 5.6g of iron from a solution of iron (2) tetraoxosulphate(6)
Answer:
0.20 mol
Explanation:
Let's consider the reduction of iron from an aqueous solution of iron (II).
Fe²⁺ + 2 e⁻ ⇒ Fe
The molar mass of Fe is 55.85 g/mol. The moles corresponding to 5.6 g of Fe are:
5.6 g × 1 mol/55.85 g = 0.10 mol
2 moles of electrons are required to deposit 1 mole of Fe. The moles of electrons required to deposit 0.10 moles of Fe are
0.10 mol Fe × 2 mol e⁻/1 mol Fe = 0.20 mol e⁻
0.20 mol of electrons is required to deposit 5.6g of iron from a solution of iron (2) tetraoxosulphate(6)
The reduction of iron from an aqueous solution of iron (II).
[tex]Fe^{+2} +2e^{-} \rightarrow Fe[/tex]
The formula for number of moles is as follows:-
[tex]Number \ of \ moles=\frac{Mass}{Molar\ mass}[/tex]
The molar mass of Fe is 55.85 g/mol. The moles corresponding to 5.6 g of Fe are:
[tex]5.6 g \times\frac{1\ mol}{55.85\ g} = 0.10 \ mol[/tex]
2 moles of electrons are required to deposit 1 mole of Fe. The moles of electrons required to deposit 0.10 moles of Fe are:-
[tex]0.10 mol Fe\times\frac{2\ mol\ e^{-} }{1\ mol\ e^{-}} = 0.20 \ mol e^{-}[/tex]
Hence, 0.20 mol of electrons is required to deposit 5.6g of iron.
To know more about:-
brainly.com/question/12513822
What is the electron configuration of titanium?
Answer:
i dont know why a, i here
Explanation:
Write the empirical formula for the hydrated KAl(SO4)2, based on your experimental results and answer to Question 2. Show all work including units.
Hint: if the ratio of moles of H2O to moles of anhydrous KAl(SO4)2 was 4, then the empirical formula would be: KAl(SO4)2•4H2O.
Answer to Question 2:
Ratio of 2:3
Answer:
Therefore mole ratio is [tex]H_{2}O[/tex] : [tex]KAl(SO_{4} )_{2}[/tex] is 12 :1
Empirical formula is [tex]KAl(SO_{4} )_{2}. 12 H_{2}O[/tex].
Explanation:
The chemical formula of a hydrate
Moles of anhydrous [tex]KAl(SO_{4} )_{2}[/tex]
Molar mass of [tex]KAl(SO_{4} )_{2}[/tex] = 258.21 g /mol
Mass of anhydrous [tex]KAl(SO_{4} )_{2}[/tex] = [mass of aluminum cup + alum after 2nd heating] –[ mass of empty cup]
= 3.5 g – 2.4 g
= 1.1 g
Moles of [tex]KAl(SO_{4} )_{2}[/tex]= mass / molar mass
= 1.1 g / 258.21 g per mol
= 0.00426 mol [tex]KAl(SO_{4} )_{2}[/tex]
The mole ratio of the H2O to [tex]KAl(SO_{4} )_{2}[/tex]
Mole ratio = moles of H2O/ moles of [tex]KAl(SO_{4} )_{2}[/tex]
= 0.05 mol H2O / 0.00462 mol [tex]KAl(SO_{4} )_{2}[/tex]
= 11.7
We can round the 11.7 to closest whole number = 12
Therefore mole ratio is [tex]H_{2}O[/tex] : [tex]KAl(SO_{4} )_{2}[/tex] is 12 :1
Empirical formula = [tex]KAl(SO_{4} )_{2}. 12 H_{2}O[/tex]
So we have 12 moles of water as the water of hydration in the empirical formula.
Alum hydrate is that the white crystalline solid after heating it'll start melting due to the water of hydration present in it then again solid will remain within the aluminum cup once all the water is given off within the sort of vapors.
b) if the scholar used 2.20 g of the sample but within the calculation, he started with 2.0 g sample then
when the mass of water is calculated using this data the mass of water is going to be higher therefore it gives more moles of water within the hydrate.
So the final answer is going to be artificially high.
