Answer:
I guess eraser is better than bread crumbs
Erasers would be better than white bread or crumbs to erase the pencil marks because they would not leave any food marks on the paper and using bread crumbs.
What is an eraser?An eraser is an object of stationary which is used to remove pencil marks from the paper. It is used during writing, when we write something wrong, we could erase or remove the writing from the paper. It is very useful for small children because they usually make mistakes while studying.
Erasers are made from the milk of rubber plants. The milk is collected from the plants, and then it is mixed with chemicals and set down, and then cut into pieces.
Thus, Erasers would be preferable to utilizing bread crumbs or white bread because they would not leave any food stains on the paper after erasing the pencil markings.
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Calculate the volume (in L) that 3.25 mol of helium gas will occupy at a temperature of 25.0 °C and a pressure of 799 mm Hg.
Answer:
V = 6.34 L
Explanation:
Given that,
Number of moles of Helium gas, n = 3.25 mol
Temperature, T = 25 °C = 298 K
Pressure, P = 799 mm Hg
We know that,
PV = nRT
Where
R is the gas constant, R = 62.4 L-mm Hg/mol K
So,
[tex]V=\dfrac{nRT}{P}\\\\V=\dfrac{3.25\times 62.4\times 25}{799}\\\\V=6.34\ L[/tex]
So, the volume of the gas is 6.34 L.
What is the name of the molecule shown below?
A) ethanol
B) ethanal
C) ethanoic acid
D) ethylamine
The name of the molecule shown is Ethanol.
What is Ethanol?Ethanol is a alcoholic substance that is formed from fermentation of glucose in the presence of yeast or microorganisms.
It has a chemical group that have methyl group, hydroxyl group OH which is bonded to carbon atom.
Therefore, The name of the molecule shown is Ethanol.
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HELP ME PLZ Which of the following describes the structure of a fish's swim bladder?
A. Expands and contracts to allow the fish to rise or sink in the water
B. Internal organ filled with liquid
c. Holds urine until it can be released into the environment
D. Internal organ filled with air sacs
8. What is the oxidation number of N in KNO3?
Answer:
The oxidation state of N in the KNO3 is +5
Explanation:
Oxidation rules:
1. Oxygen is -2, unless in peroxides.
2. Group 1 metals = +1
3. Group 2 metals = +2
4. If the molecule is neutral, all of the oxidation numbers have to add up to zero.
5. If the molecule is charged, all of the oxidation numbers have to add up to the charge of the molecule.
So, the given formula represents the salt compound formula unit of potassium nitrate: KNO3
The formula unit is uncharged.
From our rules, we know that,
O = -2
And we can find K on the periodic table, in the first group, thus giving it a +1 charge. Now let's put it all together.
K = +1
N = x
O = -2
Let's take into account the number of atoms of each element we have and make an equation since we know everything has to add up to zero since the molecules are neutral.
+1 +x+3 (-2) = 0 (notice we multiplied 3 by -2 because in the formula we have 3 atoms of oxygen with -2 charge each)
x - 5 = 0
x = 5
Therefore, the oxidation number of N in KNO3 is +5.
what is the molarity of HCL solution that has a density of 1.17g/ml at 25°?
Here, we have been given that;
$ \bf{1 ml}$ = 1.17 g$ \bf{1 l}$ = 1170 gHence, we can note that,
No. of moles of HCL (n) = $ \sf{\frac{1170}{36.5}}$(n) = 32.05
[tex] \\ [/tex]
Thus,
Molarity = 32.05 mg/LHence, molarity of the given solution will be 32.05 mg/L.
On a plateau on a heating curve, _____.
phase changes are occurring
no heat is being absorbed
all the absorbed heat is being used to overcome forces of attraction between the particles or molecules and phase changes are occurring
all the absorbed heat is being used to overcome forces of attraction between the particles or molecules
Answer:
On a Plateu on a heating curve phase changes are occuring
Explanation:
The first Phase is melting during which the temrature stays the same while water melts.Other phase changes are freezing sublimation Vaourization condensation and deposition
Hiii pls help me to write out the ionic equation
Answer:
STEP I
This is the balanced equation for the given reaction:-
[tex] 2KOH_{(aq)} + H_2SO_4{}_{(aq)} \rightarrow K_2SO_4{}_{(aq)} + 2H_2O_{(l)} [/tex]
STEP II
The compounds marked with (aq) are soluble ionic compounds. They must be
broken into their respective ions.
see, in the equation KOH, H2SO4, and K2SO4 are marked with (aq).
On breaking them into their respective ions :-
2KOH -> 2K+ + 2OH-H2SO4 -> 2H+ + (SO4)2-K2SO4 -> 2K+ + (SO4)2-STEP III
Rewriting these in the form of equation
[tex] \underline{\pmb{2K^+} }+ 2OH^- + 2H^+ + \pmb{\underline{{SO_4{}^{2-}}} \: \rightarrow \: \underline{\pmb{2K^+}}} + \underline{\pmb{SO_4{}^{2-}}} + 2H_2O [/tex]
STEP IV
Canceling spectator ions, the ions that appear the same on either side of the equation
(note: in the above step the ions in bold have gotten canceled.)
[tex] \boxed{ \mathfrak{ \red{ 2OH^-{}_{(aq)} + 2H^+{(aq.)} \rightarrow H_2O{}_{(l)}}}} [/tex]
This is the net ionic equation.
____________________________
[tex] \\ [/tex]
[tex]\mathfrak{\underline{\green{ Why\: KOH \:has\: been\: taken\: as\: aqueous ?}}} [/tex]
KOH has been taken as aqueous because the question informs us that we have a solution of KOH. by solution it means that KOH has been dissolved in water before use.[Alkali metal hydroxides are the only halides soluble in water ]
Can someone answer this ASAP?
Carbon has unique bonding characteristics that allow it to
A
form ionic bonds with any atom to form many different molecules.
B
resist bonding with other atoms and remain a pure element.
С
form chains or rings by bonding to itself and other atoms.
D
form ionic salts that make up half of the known salts on Earth.
Answer:
С. form chains or rings by bonding to itself and other atoms.
Explanation:
Carbon is an element in group 4 of the periodic table with unique bonding properties. Carbon posseses 4 valence electrons in its outer shell. This enables carbon to form covalent bonds with the atoms of other elements e.g. nitrogen, phosphorus, oxygen, hydrogen etc.
Carbon can also combine covalently with other carbon atoms i.e. C-C to form long chains and rings in a process called CATENATION. This unique property of carbon makes it the only element that can form so many different compounds.
Over a period of 2 minutes, 180 coulombs of charge pass through a resistor. What is the current through the resistor during this time?
Type the correct answer in the box. Use numerals instead of words.
The current through the resistor during this time is
A.
Answer:
Explanation:
Formula
The current = charge / time
The charge is in coulombs
The time has to be in seconds.
1 minute = 60 seconds
2 minutes = 120 seconds.
charge = 180 coulombs
current = 180 / 120
current = 1.5 amperes.
Below is a picture of two blocks made of different materials. Block A Block B grams grams If Block A is located on the Moon and Block B is located on Earth, which of the following is true about the two blocks?
a: they have the same density.
b: they have the same volume.
c: they have the same mass.
d: they have the same weight.
Answer:
A
Explanation:
this is because density is the mass per unit volume of an object
If Block A is located on the Moon and Block B is located on Earth, then the truth about the two blocks will be they have the same mass, and they have the same density. The correct option is a and c.
What is mass?Mass is a physical body's total amount of matter. By multiplying the object's volume and density, it can be determined.
Density, volume, mass, and weight are the four entities that are supplied. The volume and weight of the object on the moon will alter as a result of these entities. They will be different in the universe if he goes to Earth.
The location and gravitational field of an object do not affect its density or mass.
Thus, the correct options are a: they have the same density, and c. they have the same mass.
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A sample of hydrogen gas H2 has a volume of 5.0 L and a pressure of 1.0 atm. What is the final pressure in atmospheres if the volume is decreased to 2 L with no change in temperature and amount of gas
Answer:
2.5 atm
Explanation:
P = Pressure
V = Volume
P1V1 = P2V2
1 x 5 = P2 x 2
5 = P2 x 2
Divide both sides by 2
5/2 = P2 x 2/2
P2 = 2.5
Which of the following changes in the state of a substance results in an increase in the entropy?
Gas to solid
Gas to liquid
Liquid to solid
Solid to liquid
Answer:
the correct answer is
D. solid to liquid
write molecular formula
1)aurric cloride
2)aluminium hydroxide
3)potassium thiosulphate
4)magnesium bicarbonate
5)magnesium sulphate
6)sodium oxide
7)cuprous oxide
8)mercuric oxide
9)calcium nitrate
10)aluminium oxide
11)ferric chloride
12)ammoium oxide
13)silver chloride
14)hydrogen bromide
15)magnesium nitride
16)hydrogen peroxide
17)sodium sulphate
18)ammonium sulphate
19)ferrous sulphate
20)sodium carbonate
21)zinc carbonate
22)calcium silicate
23)zinc carbonate
24)potassium clorate
25)aluminium hydroxide
26)ammonium hydroxide
27)sodium silicate
Okay.
Here's your below answers.
1) AuCl3.
2) Al(OH)3.
3) K2S2O3.
4) Mg(HCO3)2.
5) MgSO4.
6) Na2O.
7) CuO.
8) HgO.
9) Ca(NO3)2.
10) Al2O3.
11) FeCl2.
12) (NH4)2O.
13) AgCl.
14) HBr.
15) Mg3N2.
16) H2O2.
17) Na2SO4.
18) (NH4)2SO4.
19) FeSO4.
20) Na2CO3.
21) ZnCO3.
22) CaSiO3.
23) ZnCO3.
24) KClO3.
25) Al(OH)3.
26) NH4OH.
27) Na2SiO3.
which best describes the relationship between internal energy and thermal energy
Answer:
answer is d on edge
Explanation:
nhóm nào gồm tất cả các kim loại tan trong axit sunfuric đặc nóng nhưng không tan trong axit sunfuric loãng là
Answer:Nhóm gồm tất cả các kim loại tan trong axit sunfuric đặc nóng nhưng không tan trong axit sunfuric lo
Al, Cu, Au.
Al, Fe, Cr.
Ag, Fe, Pt.
Ag, Cu, Hg.
Explanation:
The graph shows the volume of a gaseous product formed during two trials of a reaction. A diferent concentration of reactant was used during each trial, whereas the other factors were kept constant. Trial 2 Amount of Product Trial 1 Time Which of the following statements explains which trial has a lower concentration of the reactant? O Trial 1, because the average rate of the reaction is lower. O Trial 1, because this reaction lasted for a longer duration than Trial 2. O Trial 2, because this reaction was initially fast and later slowed down. O Trial 2, because the volume of product formed per unit time was higher
Answer:
A). Trial 1, because the average rate of the reaction is lower.
Explanation:
The first sentence elaborates that 'trial 1 had a lower level of concentration of the reactant that eventually led the reaction's average rate to fall.'
A trial having a higher level of concentration of a specific reactant will cause the concentration's average rate to rise. As per the graph provided, trial 2's average reaction rate is higher which shows that its concentration is greater and more reactive. However, the opposite happens in trial 1 where the amount of reactant is lesser in the concentration that leads the concentration to possess a lower rate of reaction. Thus, option A is the correct answer.
which of the following is an example of an arrthenius acid
Answer:
The common examples of Arrhenius acid includes HCl (hydrochloric acid), H2SO4 (sulphuric acid), HNO3 (nitric acid), etc.Oct 21, 2020
Explanation:
. The Ksp of barium sulfate is 1.1 × 10–10. What is the sulfate-ion concentration of a 1.0-L saturated solution of BaSO4 to which 0.025 mol of Ba(NO3)2 is added? 4.4 × 10–9M 1.0 × 10–5M 6.6 × 10–5M 2.8 × 10–12M
Answer:
[tex][SO_4^{2-}]=4.4*10^{-9}M[/tex]
Explanation:
From the question we are told that:
[tex]Ksp=1.1*10^{-10}[/tex]
Volume of [tex]SO_4^{2-}=1.O[/tex]
Moles of [tex]Ba(NO_3)^2 =0.025[/tex]
Generally the equation for Ksp is mathematically given by
[tex]Ksp=[Ba^{2+}][SO_4^{2-}][/tex]
[tex]1.1*10^{-10}=[0.025][SO_4^{2-}][/tex]
Therefore
[tex][SO_4^{2-}]=4.4*10^{-9}M[/tex]
how many grams of potassium cyanide would be needed to make a saturated solution for the volumes indicated below? The solubility of potassium cyanide is 50.0g/100ml
A. 0.150L
B. 75.0mL
C. 1.10L
D. 225mL
Jonny Jonny.
Yes papa?
Eating Sugar?
What comes next?
(A) Yes Papa
(B) No Mama
(C) Yes Mama
(D) No Papa
Answer:
(B) No papa
arafgzhzhsjdjkskbdjzjsj
Answer:
(D) No Papa
Explanation:
is this even chemistry pffttt
Scoring Scheme: 3-3-2-1 Given the starting solution had a concentration of 1.25 M, how many moles of Co[H2O]6Cl2 were available in the amount of starting solution you used
Answer:
The solution has 0.00994 moles of Co[H2O]6Cl2
Explanation:
Complete question: Given the starting solution had a concentration of 1.25 M, how many moles of Co[H2O]6Cl2 were available in the amount of starting solution you used?
mL= 7.95
Step 1: Data given
Concentration of the starting solution = 1.25 M
Starting solution = Co[H2O]6Cl2
Step 2: Calculate molar mass of Co[H2O]6Cl2
Atomic mass of Co = 58.93 g/mol
Atomic mass of H = 1.01 g/mol
Atomic mass of O = 16.00 g/mol
atomic mass of Cl = 35.45 g/mol
Molar mass of Co[H2O]6Cl2 =
1*58.93 + 12*1.01 + 6*16.00 + 2*35.45 = 237.95 g/mol
Step 3: Calculate number of moles
C = n/v
⇒with C = the Concentration of the starting solution = 1.25 M
⇒with n= the number of moles = to be determined
⇒with v = the volume = 7.95 mL = 0.00795 L
n = C * V
n = 1.25 M * 0.00795 L
n = 0.00994 moles
The solution has 0.00994 moles of Co[H2O]6Cl2
plz answer (g) i will give rating 5 and thanks who answer plz fast
Answer:
Like many common group 2 metal carbonates, magnesium carbonate reacts with aqueous acids to release carbon dioxide and water
MgCO3 + 2 HCl → MgCl2 + CO2 + H2O.
The procedure to obtain pure magnesium chloride from the reaction is as thus
Step 1: Reaction
- Leave the dilute hydrochloric acid in a beaker.
- Add Magnesium carbonate slowly until it is in excess or until no more gas seem to be getting liberated.
Step 2: Filtration
- Filter with filter paper and funnel.
- Filter off the excess magnesium carbonate as magnesium chloride will be in aqueous form (liquid) and will come out with the filtrate. The residue is the excess magnesium carbonate.
Step 3: Crystallization to obtain solid crystals from the filtrate.
- Pour filtrate solution into evaporating dish/basin
- Provide heat using Bunsen burner
- Pour solution into an evaporating basin and heat over a water bath
- Stop heating when crystals start to form
allow water to evaporate until pure crystals remain.
- Dry crystals using absorbent paper or warm oven.
Precautions
- Use personal protective equipment such as gloves, a lab coat and wear eye protection, especially when heating.
- Avoid inhaling unnecessary gases during the whole process.
Calculate the solubility of Maslog at 25€
4 30-0cm of its Saturated solution at that
temperature gave 180g of the anhydrous
C= 12. 0-46. Ma =23
Salt
Answer:
20
Explanation:
calculated saturated solutions
CORRECT ANSWER ONLY ND WILL GIVE BRAINLIEST✌
Calculate the mass of nitrogen dioxide gas that would occupy
the same volume as 10g of hydrogen gas at ē same pressure and temperature
(H= 1.0 N = 14.0 O= 16.0) GAS LAWS/MOLES
Answer:
150g
Explanation:
Assuming they are ideal gases at the same temperature and pressure, equal moles of gasses have equal volume. IN this case, if we have 10g of hydrogen gas, that is 5 moles of H2 gas. That means 5 moles og NO2 will occupy the same volume which is 5*(14.0 + 16.0*2) = 230 g
Which pair of substances would react the
fastest?
a. Copper sheet and concentrated
nitric acid.
b. Copper powder and dilute nitric acid
C. Copper powder and concentrated
nitric acid.
Answer:
C. It has the highest rate of reaction. Copper has the highest TSA/V and concentrated nitric acid has huggest num of solute
What is the percent yield of a reaction?
O A. The difference between measured and calculated amounts
OB.
The amount of produd obtained
amount possible
* 100
C. The amount of product actually obtained in a reaction
D. The amount of product that is possible from a reaction
Answer:
B. The amount of produd obtained/amount possible * 100
Explanation:
In chemistry, the yield of a chemical reaction is the quantity or amount of products obtained in that chemical reaction. It is calculated by using the following formula:
Percentage yield = Actual yield/theoretical yield × 100
- The actual yield is the amount of products got from a chemical reaction
- The theoretical yield is the amount of product got from using the balanced equation (stoichiometry).
The table below gives the equilibrium concentrations for this reaction at a certain temperature : N2(g) + O2(g) 2NO(g) what is the equilibrium constant for the reaction?
A. 1 x 10-5
B. 7 x 10-3
C. 70
D. 100
The equilibrium concentrations for the given reaction at a certain temperature will be 100.
What is equilibrium?During a reversible chemical process, chemical equilibrium is the state where there would be no net change in the number of reactants as well as products.
What is the reaction?The reaction is the process in which by the combination of more than one element new kind of element will be formed.
Given data:
The given reaction is [tex]N_{2} (g) + O_{2} (g)[/tex] → [tex]2NO(g)[/tex]
The equilibrium constant (K) = [tex][NO]^{2} /[N_{2}][O_{2}][/tex]
Put the value of the given data in the above equation.
K = [tex]=[0.002 M]^{2} / [0.65M][0.45M]\\=[4*10^{-6} ]/ [0.2950]\\= [4*10^{-6} ] / 2950*10^{-4}\\= 1.35 * 10^{-5}[/tex]
Therefore, the equilibrium constant will be 1.35 × [tex]10^{-5}[/tex]
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What happens if kinetic energy of a gas is lowered
Answer:
"If you lower the kinetic energy of a gas its temperature will decrease because temperature is a measure of the average kinetic energy of a substance."
Explanation:
Which of these hypotheses cannot be tested?
A. The percentage of salt in ocean water stays the same throughout the ocean.
O B. Doubling the amount of salt in a bread recipe will cause the dough to rise faster.
C. Cooks should use sea salt in recipes instead of regular table salt.
O D. Increasing the amount of salt in salt water will increase the boiling point.
Cooks should use sea salt in recipes instead of regular table salt.
What is a chemical reaction?
Answer:
A chemical reaction is a process in which one or more substances, also called reactants, are converted to one or more different substances, known as products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.Explanation:
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