How saliva works as a buffering agent?

Answer:

Explanation:

[tex]c = f \lambda[/tex]

where c = speed of light (3x10^8m/s)

f = frequency

[tex]\lambda[/tex] = wavelength.

We can solve that the frequency is (3x10^8)/(420 x 10^-9) = 7.14x10^14 Hz

Also, E  = hf where h = 6.62x10^-34.

So the energy is (6.62x10^-34) x  (7.14x10^14) = 4.73x10^-19 J.

Hope this helps and tell me if I made any mistakes.

Answer:

a) 2Cu(s) + S(s) → Cu₂S(s)

b) 2SO₂(g) + O₂(g) → 2SO₃(g)

c) 4HCl(aq) +  MnO₂(s) → MnCl₂(aq) + 2H₂O(l) + Cl₂(g)

d) C₆H₆(l) + 15/2 O₂(g) → 6CO₂(g) + 3H₂O(l)

Explanation:

First, we have to write the chemical formulas for reactants and products. Then, to identify which is the state of matter of each compound (liquid: l, solid: s, aqueous: aq, gas: g). Finally, we write the equation and balance the atoms.

a) Solid copper reacts with solid sulfur to form solid copper(I) sulfide.

Reactants: solid copper (Cu(s)) and solid sulfur (S(s)). Product: copper(I) sulfide (Cu₂S) because sulfur anion has two negative charges (S⁻²) and we need two copper ions with one positive charge (Cu⁺) to obtain the neutral compound.

The balanced requires a coefficient of 2 for Cu(s) to balance the 2 Cu atoms on the products side:

2Cu(s) + S(s) → Cu₂S(s)

(b) Sulfur dioxide gas reacts with oxygen gas to form sulfur trioxide gas.

Reactants: sulfur dioxide (SO₂) and oxygen gas (which is a diatomic molecule: O₂). Products: sulfur trioxide gas (SO₃(s)).

The balanced equation is:

2SO₂(g) + O₂(g) → 2SO₃(g)

We need a coefficient of 2 for SO₂ and SO₃ to balance O and S atoms.

(c) Aqueous hydrochloric acid reacts with solid manganese(IV) oxide to form aqueous manganese(II) chloride, liquid water, and chlorine gas.

Reactants: aqueous hydrochloric acid (HCl(aq)) and solid manganese (IV) oxide (MnO₂(s), because we need two oxygen anions O²⁻ to neutralize 4 positive charges in Mn IV). Products: aqueous manganese(II) chloride (MnCl₂, because we need two chloride ions Cl⁻ to neutralize two positive charges in Mn(II)), liquid water (H₂O), and chlorine gas (Cl₂, because it is a diatomic molecule).

The balanced chemical equation is:

4HCl(aq) +  MnO₂(s) → MnCl₂(aq) + 2H₂O(l) + Cl₂(g)

(d) Liquid benzene (C₆H₆) reacts with gaseous oxygen to form carbon dioxide and liquid water.

Reactants: benzene (C₆H₆) and gaseous oxygen (O₂). Products: carbon dioxide (CO₂, because C has valence IV) and liquid water (H₂O).

The balanced chemical equation is:

C₆H₆(l) + 15/2 O₂(g) → 6CO₂(g) + 3H₂O(l)

In this case, we need a coefficient of 15/2 for O₂ because on the product side there are 15 atoms of O (12 in CO₂ and 3 in H₂O).

Answer:

3.54 mol

Explanation:

Step 1: Given data

Step 2: Convert "T" to Kelvin

We will use the following expression.

K = °C + 273.15

K = 45.00°C + 273.15 = 318.15 K

Step 3: Calculate the number of moles (n) of argon gas

We will use the ideal gas equation.

P × V = n × R × T

n = P × V/R × T

n = 2.50 atm × 37.0 L/(0.0821 atm.L/mol.K) × 318.15 K = 3.54 mol

Answer:

[tex]\boxed {\boxed {\sf 976.5 \ Joules}}[/tex]

Explanation:

We are asked to find the heat energy. Since we are given the mass, specific heat, and change in temperature, we should use this formula for heat:

[tex]q=mc\Delta T[/tex]

Where m is the mass, c is the specific heat, and ΔT is the change in temperature.

We know this is a 35.0 gram piece of wire, the temperature changes from 21 °C to 52°C and the specific heat is 0.900 J/ g °C.

Therefore,

Substitute these values into the formula.

[tex]q= (35.0 \ g)(0.900 \ J/g \ \textdegree C)(31 \textdegree C)[/tex]

Multiply the first two values. The grams will cancel each other out.

[tex]q=31.5 \ J/ \textdegree C (31 \textdegree C)[/tex]

Multiply again. This time, the degrees Celsius cancel each other out, so the final units are Joules.

[tex]q=976.5 \ J[/tex]

976.5 Joules of energy were required to heat the piece of metal.

Answer:

[tex]n_{Cl_2}=0.3molCl_2[/tex]

Explanation:

Hello there!

In this case, according to the given chemical reaction whereas the sodium chloride is in a 2:1 mole ratio with chlorine, the required moles of the later are computed as shown below:

[tex]n_{Cl_2}=0.6molNaCl*\frac{1molCl_2}{2molNaCl}[/tex]

So we cancel out the moles of NaCl to obtain:

[tex]n_{Cl_2}=0.3molCl_2[/tex]

Best regards!

Answer: 56.2 g of Aluminium is needed to react fully with 100 grams of sulphur.

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} S=\frac{100g}{32g/mol}=3.125moles[/tex]

The balanced chemical equation is:

[tex]2Al+3S\rightarrow Al_2S_3[/tex]  

According to stoichiometry :

3 moles of [tex]S[/tex] require = 2 moles of [tex]Al[/tex]

Thus 3.125 moles of [tex]S[/tex] will require=[tex]\frac{2}{3}\times 3.125=2.08moles[/tex]  of [tex]Al[/tex]  

Mass of [tex]Al=moles\times {\text {Molar mass}}=2.08moles\times 27g/mol=56.2g[/tex]

Thus 56.2 g of Aluminium is needed to react fully with 100 grams of sulphur.

Answer:

6.37

Explanation:

Answer:

high ph

Explanation:

if you have high conc of H+ ph is low therefore acidic but if vice versa basic

high ph

Answer:

A.................. I think the answer

Answer:

No you have to use a new email unless you delete the other accaount

Explanation:

hope that helps

Answer:

[tex]V_2=0.153L[/tex]

Explanation:

Hey there!

In this case, according to the equation for dilution process, in which the moles of the solute remain the same after the addition of additional solvent:

[tex]M_1V_1=M_2V_2[/tex]

Thus, by solving for the new volume, V2,  of the base, NaOH, we can obtain:

[tex]V_2=\frac{M_1V_1}{M_2}=\frac{0.09L*0.850M}{0.500M}\\\\V_2=0.153L[/tex]

Best regards!

Explanation:

Well i mean clothes so cells make tissues which help organs clothes can technically help you if you fall it has layers so it woulf be as a cell?

Answer:

Explanation:

The molarity of a solution when given the number of moles the substance and it's volume can be found by using the formula

[tex]c = \frac{n}{v} \\ [/tex]

n is the number of moles

v is the volume in L

We have

[tex]c = \frac{0.4}{9.79} \\ = 0.04058...[/tex]

We have the final answer as

Hope this helps you

Answer:

Sodium becomes a positive ion and chlorine becomes a negative ion. ... Each atom is neutrally charged, which means that each atom has the same number of protons and electrons.

Explanation:

I think it's D

Explanation:

if you think abt it strength training means weights and stuff so I dont think it increases flexibility. it's that or letter C

Answer:

m = 49.8 g

Explanation:

Hello there!

In this case, for this calorimetry processes we can define the involved heat in terms of mass, specific heat and temperature as shown below:

[tex]Q=mC\Delta T[/tex]

Thus, given the heat, final and initial temperature and specific heat of water (4.184), the mass of water can be computed as shown below:

[tex]m=\frac{Q}{C\Delta T}\\\\m=\frac{12500J}{4.184\frac{J}{g\°C}(75\°C-15.0\°C)} \\\\m=49.8g[/tex]

Best regards!

Answer:

0.67 cm³

Explanation:

We can solve this problem by using the definition of density:

We can rearrange the equation and isolate volume:

As we are given both the mass and the density, we can now calculate the volume:

Answer:

[tex]n_{NH_3}^{produced}=6.3molNH_3[/tex]

Explanation:

Hello there!

In this case, according to the given chemical reaction, it is possible for us to use the 1:2 mole ratio of nitrogen to ammonia to calculate the moles of the latter that are produced when reacting 3.15 moles of the former with hydrogen as shown below:

[tex]n_{NH_3}^{produced}=3.15molN_2*\frac{2molNH_3}{1molN_2}[/tex]

Thus, by solving the equation we obtain:

[tex]n_{NH_3}^{produced}=6.3molNH_3[/tex]

Best regards!

Answer:

χsolvent = 1.0000 - 0.1000 = 0.9000

Use Raoult's Law:

Psolution = (χsolvent) (P°solvent)

x = (0.900) (25.756)

x = 23.18 mmHg (to four sig figs)

The vapor pressure of an aqueous solution is  x = 23.18 mmHg (to four sig figs)

χsolvent = 1.0000 - 0.1000 = 0.9000

Use Raoult's Law:

P solution = (χsolvent) (P°solvent)

x = (0.900) (25.756)

x = 23.18 mmHg (to four sig figs)

An aqueous answer is one in which the solvent is liquid water. that is, solute (dissolved) ions and molecules are surrounded by water molecules and integrated into the network of bonds within the water. The dissolved species then spread in the course of the water.

A solution wherein water is the solvent is called an aqueous solution. although water is an exceptional solvent, now not the whole thing dissolves comfortably in the water.

Aqueous' in a chemical equation suggests that the cloth dispersed in water (an answer in water). As an example, when we pour sodium hydroxide answer into dilute hydrochloric acid, we get an aqueous solution of sodium chloride. The liquid is used to signify the formation of liquid materials in response.

Learn more about the aqueous solution here: https://brainly.com/question/19587902

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Answer:

The answer is the C. Photic zone.

Explanation:

I wish you good luck! :>

Answer: C photic zone

Explanation:

Answer:

A its a step by step equation the answer is A

Answer:

C is the correct answer.

Explanation:

We can eliminate some answers immediately:

A is incorrect because nitrogen and hydrogen do not change their identity, they just combine into a new molecule that contains them. Notice how there are 2 nitrogen atoms and 6 hydrogen atoms on both sides of the equation.

B is incorrect because the first law of thermodynamics tells us that matter and energy will always be conserved, so the mass of the products must be equal to the mass of the reactants, not less than the mass of the reactants.

C is correct because balanced chemical equations help chemists predict how much product will form from certain amounts of reactants.

D is incorrect because this equation is showing the exact opposite. Molecular hydrogen and nitrogen can combine stoichiometrically to form ammonia.

Answer:

B

Explanation:

to find the new rate when the concentration of reactants changes

Answer:

m = 200.6 gr

Explanation:

CH2COOH : n = 3.4 mol

Mr = 12 + 2 + 12 + 2×16 + 1 = 59

n= m / Mr => m = n× Mr => m = 3.4×59 => m = 200.6 gr

Answer:

I think

Explanation:

N for nitrogen

P for phosphorus

Br for bromine

K for potassium

Mg for magnesium

Answer:Occluded fronts usually form around areas of low atmospheric pressure. There is often precipitation along an occluded front from cumulonimbus or nimbostratus clouds. Wind changes direction as the front passes and the temperature either warms or cools.

Explanation:

Answer:

Why aren't diamonds found evenly distributed on Earth? Diamonds are only formed under specific conditions that involve geological processes, such as volcanic activities and plate movements. Since these conditions and processes only take place in certain areas, you can only find diamonds in these special places.

Explanation:

Answer:

True

Explanation:

In an alpha decay, the isotope of an element releases two protons and two neutrons. An alpha particle or helium has two protons and two neutrons and hence, in an alpha decay an alpha particle is released.

Hence, the given statement is true