Answer:
A lower pH of the mouth creates bad bacteria that eventually lead to decay of the tooth.
It can be prevented by avoiding food that causes acidity.
Explanation:
Tooth decay is caused by the pH level in the mouth dropping below 5.5, meaning it is acidic. It can be prevented by brushing your teeth as toothpaste is an alkali which will neutralise the pH level in your mouth.
Hope this helps
Calculate the percentage of all elements in Fel(OH)3
Please help, I will mark the answer with brainlist...
Answer: 30.06% is your answer.
I hope this helps.
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explain why an indicator is used in titration
Answer:
Titrations. Because a noticeable pH change occurs near the equivalence point of acid-base titrations, an indicator can be used to signal the end of a titration. When selecting an indicator for acid-base titrations, choose an indicator whose pH range falls within the pH change of the reaction.
Hope it helped!!
In the movie bee movie how does the bee berry communicate
Answer:
they stick together as a group and that they berly fought or argue
Answer:first get a jar
Explanation:
Patrick that’s a jokers side special
What takes place in a cell's mitochondria ?
A.cellular respiration
B.DNA replication
C.protein synthesis
D.photosynthesis
I NEED HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
c
Explanation:
the mitochodria is the protien power house of the cell
3. Sugar solution(sugar + water) is a homogeneous mixture and sugar can be separated from water through evaporation .Comment.
Plz, answer
Answer:
water is the answer
Explanation:
The sugar and water mix to make sweet water but the sun extracts the sugar from the water leaving only normal water
Answer:
water can be evaporated
Explanation:
the water will be evaporated leaving only the sugar residue behind.
why is copper different than copper ore gives me reasons. Do this asap
Answer:
copper cathodes are normally referred to when talking about copper. Cathode is the purest form of copper and is the feedstock used to produce copper wire, cable, sheet, strip, tube, etc.
Explanation:
A 500ml bottle contains 2.50 moles of gas. What is the new volume when the number of miles is increased 5.00 moles?
Answer:
The new volume is 1,000ml
Explanation:
Mathematically, we know that the number of moles per ml(volume) should be constant irrespective of the increase.
Initially, we have a volume of 500 ml and number of moles of 2.5 moles
The ratio of the number of moles to the volume is 2.5/500 = 0.005 mole/ml
Now, this is expected to remain the same even if we have an increment.
let’s call the new volume x
0.005 mol/ml = 5 moles/x ml
x = 5/0.005 = 1,000 ml
4. Why does ammonia, NH3, behave as a base when it reacts with an acid?
A It accepts a neutron and becomes NH3+.
B It accepts a proton and becomes NH4+.
OC It donates a proton and becomes NH2
B is the answer ,ammonium accepts a proton and becomes ammonium ion
Why are the electrons in a bond between carbon and oxygen, C-O, closer to the oxygen atom than the carbon atom?
Answer:
Because electronegativity of Oxygen is higher than electronegativity of Carbon.
Explanation:
The electrons in a bond between carbon and oxygen, C-O, closer to the oxygen atom than the carbon atom because electronegativity of Oxygen is higher than electronegativity of Carbon.
What do all pure substances have in common?
Answer:
All the pure substances are made up of atoms and group of atoms known as molecules. They also have weight, volume and colour white solids also have the shape and hardness or texture. Pure substances also have points at which they boil and solidify.
Answer:
Pure substances are defined as substances that are made of only one type of atom or molecule. The purity of a substance is the measure of the extent to which a given substance is pure.
Explanation:
Respiration occurs in the __________
Respiration occurs in the mitochondria
Answer:
mitochondria
Explanation:
Respiration happens in the cells of plants, animals and humans, mainly inside mitochondria.
1
Net ionic equations remove spectator ions and shows only the chemical species that are involved in the chemical reaction. Write the net ionic equation for the following acid base reaction.
Molecular Equation: 2 HCl (aq) + Mg(OH)2 (aq) → MgCl2 (aq) + 2 H2O (l)
Complete Ionic: 2 H+ (aq) + 2 Cl– (aq) + Mg2+ (aq) + 2 OH– (aq) → Mg2+ (aq) + 2 Cl– (aq) + 2 H2O (l)
Net Ionic Equation: ______________________________________________________
Answer:
The reaction of an acid and a base is called a neutralization reaction. ... However, in the reaction between HCl(aq) and Mg(OH) 2(aq), additional molecules of HCl and ... First, we will write the chemical equation with the formulas of the reactants ... The chloride ions are the only spectator ions I THINKS
Explanation:
For which purpose do biochemist insert human genes into bacteria
Answer: to find a cure for the common cold to produce insulin for diabetics
Explanation: It has helped many people
The chemical formula is different from the empirical formula in
A) H2O2
B) CO2
C) CO.
OD) H20.
Answer:
A) H2O2
Explanation:
Hydrogen peroxide is written as H2O2, which is the chemical formula of the compound, but this can be simplified. Since both H and O have the subscript of 2, they can be simplified to 1, so the empirical formula for H2O2 would be just H and O together (Brainly won't let me say the empirical form because it has the same spelling as a swear word). Thus, the empirical formula and chemical formula are different.
In the case of the other options, they are all in their simplest form and cannot be simplified further, so they are already in their empirical form, so both the chemical form and empirical form are the same.
A.
B.
C.
D.
what’s the correct answer?
Answer:
C Gamma Rays
Explanation:
Radio waves, on the other hand, have the lowest energies, longest wavelengths, and lowest frequencies of any type of EM radiation. In order from highest to lowest energy, the sections of the EM spectrum are named: *gamma rays* ,X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves.
Name the process that releases carbon dioxide into the atmosphere.
Step 3: Measure Solubility in Cold Water
10
0
-10
80
100 m
60
-40
20
Temperature of the water to the nearest degree:
ANSWER IS 2°C. !!!
Answer:
2 degrees celcius
Explanation:
What volume will be occupied by 11.7 g of Helium in a balloon at an altitude of 10.0 km if the air pressure is 0.262 atm and the temperature is -50.0 °C?
Answer: 204 L
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 0.262 atm
V = Volume of gas = ?
n = number of moles = [tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{11.7g}{4g/mol}=2.92[/tex]
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]-50^0C=(273+(-50))K=223K[/tex]
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{2.92\times 0.0820 L atm/K mol\times 223K}{0.262atm}=204L[/tex]
Thus volume occupied by 11.7 g of Helium in a balloon is 204L
15. Calculate the hydrogen ion concentration of a
solution whose pH is 2.4
A 3.6 x 0.01
B 2.5 x 0.0001
C 2.5 x 0.01
D 7.0 x 0.01
Answer:
Explanation:
pH = − log [H+] , we can solve for [H+] as,
− pH = log [H+] ,
[H+] = 10^−pH,
so PH =2.4 in you case is
[H+] = 10^-2.4 =0.00398
The option are not correct it looks
a sample of a compound that contains only the elements C,H and N is completely burned in O2 to produce 44g of CO2, 45g of H2O, and some NO2. A possible empirical formula of the compound is A. CH2N B.CH5N C.C2H5N D.C3H3N2
Answer:
B. CH₅N
Explanation:
The combustion reaction of a compound CₐHₓNₙ with O₂ is:
CₐHₓNₙ + O₂ → a CO₂ + X/2 H₂O + n NO₂
Where 1 mole of CₐHₓNₙ with an excess of O₂ produce a moles of CO₂, X/2 moles of H₂O and n moles of NO₂
Thus, you need to convert the mass of CO₂ and H₂O to moles to find the C:H ratio and determine a possible empirical formula thus:
Moles CO₂ (Molar mass 44g/mol):
44g ₓ (1mol / 44g) = 1 mole CO₂ = 1 mole C
Mole of H₂O (Molar mass 18g/mol):
45g ₓ (1 mol / 18g) = 2.5 moles H₂O = 5 moles H
Thus, in the compound you have 5 moles of H per mole of C, and a possible empirical formula is:
B. CH₅NThe only structure that meet this C:H ratio
The most likely empirical formula for the one that exemplifies a specimen of the compound containing the element C, H, and N which are completely combusted in oxygen to generate 44g Co2, 45g of H2O, and a little NO2 would be:
B). CH₅N
The reaction of combustion taking place in the compound CₐHₓNₙ using [tex]O_{2}[/tex] (oxygen) would be:
[tex]C_{a} H_{x} N_{n} + O_{2}[/tex] → [tex]aCO_{2} + X/2 H_{2}O + nNO_{2}[/tex]
In this reaction, 1 mole belonging to [tex]C_{a} H_{x} N_{a}[/tex] having additional [tex]O_{2}[/tex] (oxygen) leads to generating '[tex]a[/tex]' moles of [tex]CO_{2}[/tex] (Carbon dioxide), [tex]X/2[/tex] number of moles of [tex]H_{2}O[/tex](Hydrogen), and n amount of moles of Nitrogen([tex]N[/tex]).
Therefore, it will be required to transform the mass of [tex]CO_{2}[/tex] and [tex]H_{2}O[/tex] in the form of moles to deduce the ratio C:H to look for the likely empirical formula.
[tex]CO_{2}[/tex] Moles (∵ Molar mass [tex]= 44g/mol)[/tex]
= [tex]44g[/tex] × [tex](1mol/44g)[/tex]
[tex]= 1 mole[/tex] of [tex]CO_{2}[/tex]
[tex]= 1 mole[/tex] of C
[tex]H_{2}O[/tex] Moles (∵ Molar mass =[tex]18g/mol)[/tex]
[tex]= 45g[/tex] ₓ [tex](1 mol / 18g)[/tex]
[tex]= 2.5 moles[/tex] [tex]H_{2}O[/tex]
[tex]= 5[/tex] [tex]moles of H[/tex] because (H * 2)
∵ The C:H ratio is 1:5 implying that formula would include 5 H moles and 1 C mole. So, CH₅N is the correct option.
Thus, option B is the correct answer.
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In the Lewis dot structure for H2CCH2, how many bonds are between the carbon atoms?
3
4
1
2
Answer:
2
Explanation:
The compound H2CCH2 has the condensed formula C2H4. The name of the compound is ethene. The compound is unsaturated, that is, it contains multiple bonds. The compound has a formula which fits into the general molecular formulae of alkenes (olefins) which his CnH2n.
Olefins have a double bonds between the carbon atoms. That is , the two carbon atoms in Olefins are connected via a double covalent bond. This now implies that the two carbon atoms in ethene (C2H4) are connected by two covalent bonds in the lewis structure of the molecule as is common for Olefins.
In the Lewis dot structure for [tex]\rm H_2CCH_2[/tex], there is one covalent bond present between the carbon atoms. The correct answer is option c.
A dot structure is a method of depicting an atom's valence electrons by placing dots around the atomic symbol. One valence electron is represented by each dot.
In the Lewis dot structure of [tex]\rm H_2CCH_2[/tex], there is one bond between the carbon atoms. This is because each carbon atom has two electrons in its valence shell, and each hydrogen atom has one electron in its valence shell.
The two carbon atoms share two electrons to form one covalent bond, and each carbon atom also shares one electron with a hydrogen atom to form two additional covalent bonds.
Therefore, the correct answer is option c. There is one bond (covalent bond) between the carbon atoms in the Lewis dot structure for [tex]\rm H_2CCH_2[/tex].
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For neap tides, what must the angular alignment be between the sun, earth and moon?
Answer:
The angular alignment is 90 degrees
Explanation:
The neap tide is a type of tide which occurs around seven days after a spring tide. This type of tide happens twice every month.
The tide is usually moderate and it exists when the sun and moon are usually at right angles to each other when it occurs. A right angle is also known as 90 degrees which validates the tide occurring at an angle 90.
Only purple flowers result from a cross between purple-flowered pea plants and white-flowered pea plants. What does this indicate?
Purple flowers are a mutation
Purple flowers are recessive
Purple flowers are dominant
Purple flowers are hybrid
Answer:
Purple flowers are dominant
Explanation:
The melting point of three solids X,Y and Z are 298K, 314 K and 398K respictively.Arrange these in increasing order of their inter particle force of attraction
Answer:
Explanation:
The higher the melting point of a substance, then the higher the force of attraction. Which means there is direct relationship between the melting point and force of attraction.
The increasing order of interparticle force of attraction of the the three particles are
Z(398) Y(314) X (298)
I.e Particle " Z " have highest melting point, follows by particle "Y" follows by particle "X
NOTE: The melting point of a substance refers to the
temperature whereby there there is a change from solid state to liquid state, it is dependent on the pressure of the system
WILL MARK BRAINLIEST IF GOOD EXPLANATION...
Ethyl acetate is a sweet-smelling solvent used in varnishes and fingernail polish remover. It is produced industrially by heating acetic acid and ethanol
together in the presence of sulfuric acid, which is added to speed up the
reaction. The ethyl acetate is distilled off as it is formed. The equation for the
process is as follows.
CH3COOH + CH3CH2OH --> CH3COOCH2CH3 + H2O
Determine the percentage yield in the following cases:
a. 68.3 g of ethyl acetate should be produced but only 43.9 g is recovered.
b. 0.0419 mol of ethyl acetate is produced but 0.0722 mol is expected. (Hint:
Percentage yield can also be calculated by dividing the actual yield in moles
by the theoretical yield in moles.)
c. 4.29 mol of ethanol is reacted with excess acetic acid, but only 2.98 mol of
ethyl acetate is produced.
d. A mixture of 0.58 mol ethanol and 0.82 mol acetic acid is reacted and 0.46
mol ethyl acetate is produced. (Hint: What is the limiting reactant?)
Answer:
a) 64.27%
b) 58%
c) ethanol is the limiting reactant
d) ethanol is the limiting reactant
Explanation:
We have to note that the expected yield is the theoretical yield while the actual mass or amount of product formed is the actual yield.
a) theoretical yield=68.3g
Actual yield= 43.9 g
Percentage yield= 43.9/68.3 ×100
Percentage yield= 64.27%
b) theoretical yield= 0.0722 moles
Actual yield = 0.0419
Percentage yield= 0.0419/0.0722 × 100
Percentage yield= 58%
c) note that the limiting reactant yields the least number of moles of product
Ethanol will be the limiting reactant since it is not present in excess.
d) from the reaction equation;
1 mole of acetic acid produces 1 mole of ethyl acetate
0.58 moles of ethanol produces 0.58 moles of ethyl acetate
1 mole of acetic acid yields 1 mole of ethyl acetate
Hence 0.82 moles of acetic acid yields 0.82 moles of ethyl acetate
Hence ethanol is the limiting reactant.
The density was of a solution of sulfuric acid is 1.285g/cm3 and it is 38.08% (by weight) acid. How many millimeters of the acid solution do you need to supply 125 grams of sulfuric acid?
Answer:
255.5cm³
Explanation:
A solution that is 38.08 % by weight has 38.08g of sulfuric acid per 100g of total solution. Thus, mass of solution you need to obtain 125g is:
125g H₂SO₄ × (100g solution / 38.08g H₂SO₄) = 328.3g of solution
As density of the solution is 1.285g / cm³, the volume of 328.3g is:
328.3g × (1cm³ / 1.285g) = 255.5cm³
does a periodic table indicate the occurrence of elements
Answer:
no
Explanation:
it only shows the atomic number and basically the chemical behavior of the element
What is the name of Al2(CO3)3 ?
Answer: Aluminum Carbonate
Explanation:
Answer:
Aluminum carbonate.
Explanation:
It is an aluminum salt form of carbonic acid.
The diagram shows Niels Bohr’s model of an atom.
A small green circle labeled Proton is surrounded by 4 concentric circles. The space inside the first concentric circle is labeled N = 1; the space between the first and second circle is labeled N + = 2; between the second and third N = 3, and between the third and fourth N = 4. Oblong gray shapes labeled Electron appear on the second and third concentric circles.
What happens when the electron moves from the first energy level to the second energy level?
Energy is absorbed, and an emission line is produced.
Energy is released, and an emission line is produced.
Energy is absorbed by the atom.
Energy is lost from the atom.
Answer:
Energy is absorbed by the atom.
Explanation:
An acid is added to water, and a new equilibrium is established. What is the system after the acid is added? A. pH w = 1 x 10-14 B. pH w -14 C. pH > pOH and Kw = 1 x 10-14 D. pH > pOH and Kw > 1 x 10-14
Answer:
C. pH > pOH; Kw = 1.0 * 10^-14
Explanation:
The ion product of water, Kw = [H+]*[OH-] = 1.0 * 10^-14. It is a constant.
When an acid or base is added to water, its ion product does not change as it a constant. However, the relative concentrations of H+ ions and OH- ions will change depending on whether an acid or base is added to water.
When an acid is added to water, the concentration of H+ ions increases while that of OH- ions decreases, and vice versa.
Therefore, in the above situation where an acid is added to water, pH > pOH; Kw = 1.0 * 10^-14