what is the answer i need help

Answer:

2 is the answer your welcom

Answer:

Percent yield = 87.5%

Explanation:

Given data:

Number of moles of Fe(NO₃)₃ = 2.5 mol

Number of moles of Na₂CO₃ = 3.6 mol

Actual yield of NaNO₃ = 6.3 mol

Percent yield of NaNO₃ = ?

Solution:

Chemical equation:

2Fe(NO₃)₃ + 3Na₂CO₃        →     Fe₂(CO₃)₃ + 6NaNO₃

now we will compare the moles of both reactant with NaNO₃.

                   Fe(NO₃)₃          :              NaNO₃

                       2                   :                  6

                     2.5                  :            6/2×2.5 = 7.5

                  Na₂CO₃             :              NaNO₃

                       3                   :                  6

                     3.6                  :            6/3×3.6 = 7.2

Theoretical yield of NaNO₃ is 7.2 mol.

Percent yield:

Percent yield = actual yield / theoretical yield ×100

Percent yield = 6.3 mol / 7.2mol ×100

Percent yield = 87.5%

Answer:

H20

Explanation:

Answer:

The answer is H20

Explanation:

Answer:

160 mL

Explanation:

Given data:

Molarity of NaOH = 0.105 M

Volume of H₂SO₄ = 40.0 mL (40.0/1000 = 0.04 L)

Molarity of H₂SO₄ = 0.210 M

Volume of NaOH required = ?

Solution:

Number of moles of of H₂SO₄:

Molarity = number of moles / volume in L

0.210 M = number of moles / 0.04 L

Number of moles = 0.210 mol/L × 0.04 L

Number of moles = 0.0084 mol

now we will compare the moles of H₂SO₄  with NaOH.

                     H₂SO₄          :           NaOH

                        1                 :             2

                    0.0084          :         2/1×0.0084 = 0.0168 mol

Volume of NaoH:

Molarity = number of moles / volume in L

0.105 M =  0.0168 mol / Volume in L

Volume in L =  0.0168 mol / 0.105 M

Volume in L =  0.16 L

Volume in mL:

0.16 L × 1000 mL/ 1L

160 mL

The volume of the NaOH solution required for the reaction is 160 mL

The balanced equation for the reaction is given below:

H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O

From the balanced equation above,

Finally, we shall determine the volume of the base, NaOH required for the reaction.

MaVa / MbVb = nA/nB

(0.21 × 40) / (0.105 × Vb) = 1 / 2

8.4 / (0.105 × Vb) = 1 / 2

Cross multiply

0.105 × Vb = 8.4 × 2

0.105 × Vb = 16.8

Divide both side by 0.105

Vb = 16.8 / 0.105

Vb = 160 mL

Thus, the volume of the base, NaOH required for the reaction is 160 mL

Learn more about stoichiometry: https://brainly.com/question/21182105

Answer:

Option E. Zirconium

Explanation:

From the question given above, the following data were obtained:

Length of side (L) of cube = 0.2 cm

Mass (m) of cube = 52 mg

Name of the unknown metal =?

Next, we shall determine the volume of the cube. This can be obtained as follow:

Length of side (L) of cube = 0.2 cm

Volume (V) of the cube =?

V = L³

V = 0.2³

V = 0.008 cm³

Next, we shall convert 52 mg to g. This can be obtained as follow:

1000 mg = 1 g

Therefore,

52 mg = 52 mg × 1 g / 1000 mg

52 mg = 0.052 g

Thus, 52 mg is equivalent to 0.052 g.

Next, we shall determine the density of the unknown metal. This can be obtained as follow:

Mass = 0.052 g.

Volume = 0.008 cm³

Density =?

Density = mass / volume

Density = 0.052 / 0.008

Density of the unknown metal = 6.5 g/cm³

Comparing the density of the unknown metal i.e 6.5 g/cm³ with those given in table in the above, we can conclude that the unknown metal is zirconium

Answer:

This is all up to you

Explanation: This question is up to you because you may think both or just one.

Answer:

Most of the atom is empty space. The rest consists of a positively charged nucleus of protons and neutrons surrounded by a cloud of negatively charged electrons. The nucleus is small and dense compared with the electrons, which are the lightest charged particles in nature.

Answer:

Wave 2

Explanation:

Higher frequency  means more energy per second, And wave 2 has higher frequesncy

please mark brainliest I’m almost at expert level

Answer:

I believe it is wave 2

Explanation:

As you can see in the graph, wave two happens to be more frequent. There are well, more waves than the first graph. Please forgive me if I am wrong. I tried my best to explain

Answer:

2.78 x 10²³

Explanation:

1 mole contains 6.02 x 10²³ hydrogen atoms => 0.46 mole contains 0.46(6.02 x 10²³) hydrogen atoms or 2.78 x 10²³ atoms.

Caution => When to use H vs H₂ => This problem is specific for 'hydrogen atoms' but some may simply say hydrogen. In such cases use H₂ or 'molecular hydrogen' is the focus. it's a matter of semantics, H vs H₂.    

Answer:

disulfur heptoxide

Explanation:

Answer:

Light

Explanation:

1 They were not albe to see at night because it  was dark so the lack of light caused them to use echolocation.

Hope this helps

Answer:

A

Explanation:

Answer:

think it is D

Explanation:

hope this helps

Answer:

0.00000000910938;

9.109380 * 10^-9

Explanation:

Given the question :

Given :

1.602176*10-¹⁹/ 1.758820*10¹¹

The numbers are expressed in the form:

A * 10^b ; Where;

A = Coefficient ; 10 = base ; b = exponent

The Coefficients can be divided directly as :

1.602176 / 1.758820 = 0.9109380

Using the division law of indices, the exponents acn be worked out as follows since they have the same base :

10^-19 / 10^-11 = 10^(-19 - (-11)) = 10^(-19+11) = 10^-8

Thus, we have ;

0.9109380 × 10^-8

In standard form:

9.109380 * 10^-9

In Expanded form:

10^-8 = 0.00000001

0.9109380 * 0.00000001 = 0.00000000910938

0.000000009 +

0.0000000001 +

0.00000000000 +

0.000000000009 +

0.0000000000003 +

0.00000000000008

__________________

0.00000000910938

___________________

Answer:

The correct answer is D. Ask a question that can be answered by making observations.

Explanation:

Basically, in order to develop a testable hypothesis, scientists must adhere to the guidelines of the scientific method.

The scientific method is usually understood to be a so-called hypothetical-deductive method, the core of which is to make hypotheses based on observations or measurements, to make predictions based on them and to check the validity of predictions by repeated experiments. More generally, the scientific method is a general way of obtaining solid knowledge, using many means of proof, both empirical and theoretical, to achieve certainty. The scientific method is a widely recognized tool in the scientific community for seeking objectivity, reliability and transparency in research.

Answer: Temperature measures thermal energy, and heat is the flow of thermal energy

Explanation:

Heat describes the transfer of thermal energy between molecules within a system. Heat measures how energy moves or flows. It is measured in Joules.

Temperature measures the hotmess or coldness of a body or how much thermal energy it contains . Temperature describes the average kinetic energy of molecules within a material or system. It is measured in Celsius (°C), Kelvin(K), or Fahrenheit (°F).

Thus the correct option is Temperature measures thermal energy, and heat is the flow of thermal energy

Answer:

its c

Explanation:

edg 2021

The mass of the Pbl2 : 1308.87

Given

18.2 mL of a 0.156 M Pb(NO3)2

26.2 mL of a 0.274 M KI

Reaction

Pb(NO3)2 (aq) + 2 KI (aq) - Pbl2 (s) + 2 KNO3

Required

the mass of the Pbl2

Solution

mol Pb(NO3)2 = 18.2 x 0.156 = 2.8392 mlmol

mol KI = 26.2 x 0.274 =7.1788 mol

Limiting reactant Pb(NO3)2(smaller ratio of mol : reaction coeffiecient)

mol Pbl2 based on limiting reactant (Pb(NO3)2)

From equation, mol ratio of Pb(NO3)2 : Pbl2 = 1 : 1, so mol Pbl2=mol Pb(NO3)2=2.8392

Mass Pb(NO3)2 :

[tex]\tt mass=mol\times MW\\\\mass=2.8392\times 461\\\\mass=1308.87~grams[/tex]

Answer:

im going to go with the water is less dense than the glycerol

Explanation:

Answer:

2Al(NO_{3} )_{3} + 3K_{2}SO_{4} ----> Al_{2}(SO_{4})_{3} + 6KNO_{3}

Explanation:

[tex]2Al(NO_{3} )_{3} + 3K_{2}SO_{4} ----> Al_{2}(SO_{4})_{3} + 6KNO_{3}[/tex]

Explanation:

Molar mass of Cu = 63.5g/mol

Moles of Cu

= 5.8g / (63.5g/mol) = 0.091mol (B)

The number of moles present in a 5.8 g sample of copper is equal to 0.0913 mol. Therefore, option B is correct.

A mole can be defined as an international scientific unit that is used to determine for given count of particles. The particles are commonly identical entities but they are individually distinct.

A mole of the substance can be used to evaluate a large number of atoms, molecules, or particular particles. The amount of material can be measured as chemical entities of a substance in a sample.

The number of units in 1 mole of a material is equal to 6.023×10²³ which is called Avogadro’s constant.

Given,  the mass of the copper = 5.8 g

The mass of one mole of copper = 63.5 g

We can calculate moles as, n = Mass/molar mass

Then, the number of moles of copper = 5.8/63.5 = 0.0913 mol

Therefore, the number of moles of copper is 0.0913 mol.

Learn more about the mole, here:

brainly.com/question/26416088

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Answer:

[tex]\boxed {\boxed {\sf 7.89*10^{-4} \ mol \ Pb}}[/tex]

Explanation:

To convert from moles to atoms, we must use Avogadro's Number. Avogadro's Number

1. Set up ratio

We can use Avogadro's Number as a fraction or ratio.

[tex]\frac{6.022*10^{23} \ atoms \ Pb}{1 \ mol \ Pb}[/tex]

2. Convert atoms to moles

Multiply the given number of atoms by the ratio.

[tex]4.75 *10^{20} \ atoms \ Pb *\frac{6.022*10^{23} \ atoms \ Pb}{1 \ mol \ Pb}[/tex]

Flip the fraction so that the atoms of lead can cancel each other out.

[tex]4.75 *10^{20} \ atoms \ Pb *\frac{1 \ mol \ Pb}{6.022*10^{23} \ atoms \ Pb}[/tex]

[tex]4.75 *10^{20} *\frac{1 \ mol \ Pb}{6.022*10^{23} }[/tex]

[tex]\frac{4.75 *10^{20} \ mol \ Pb}{6.022*10^{23} }[/tex]

[tex]7.88774494*10^{-4} \ mol \ Pb[/tex]

3. Round

The original measurement of 4.75 had 3 significant figures (4, 7, and 5).

We must round our answer to 3 sig figs, which is the hundredth place for the number found.

[tex]7.88774494*10^{-4} \ mol \ Pb[/tex]

The 7 in the thousandth place tells us to round the 8 up to a 9 in the hundredth place.

[tex]7.89*10^{-4} \ mol \ Pb[/tex]

There are 7.89*10⁻⁴ moles of lead in 4.75*10²⁰ atoms of lead.

Answer:

0.05 M

Explanation:

Mass of benzoic acid= 0.158g

Volume of benzoic acid= 100 mL

Volume of sodium hydroxide = 27.84mL

Molar mass of benzoic acid= 122g/mol

Number of moles of benzoic acid= 0.158g/122g/mol= 1.3 × 10^-3 moles

C= no of moles/volume

C= 1.3 × 10^-3 moles × 1000/100

C= 0.013M

So;

Volume of acid VA = 100mL

Concentration of acid CA= 0.013M

Volume of Base VB = 27.84mL

Concentration of Base CB= ???

Number of moles of acid NA =1

Number of moles of Base NB= 1

From;

CAVA/CBVB= NA/NB

CAVANB= CBVBNA

CB= CAVANB/VBNA

CB= 0.013 × 100 × 1/27.84 × 1

CB= 0.05 M

Answer:

the celery would change colour!

Explanation:

Answer:

The segment of this graph that shows a decreasing velocity is the EF segment. AB and DE segments show that whatever was moving, in these segments was stopped. The segment BC shows an increase in velocity - the metres travelled were always more as the time went by.

Explanation:

Answer:

A highly positive ion was attracted to a membrane and their locations is explained in details.

Explanation:

1.

The Head of a lipid is hydrophilic (polar). This cover can be bearing negative or positive charges. This is that charge that creates the head hydrophilic(communicate with water(a polar molecule, including negative and positive unfair charges).

The tail is hydrophobic (non-polar). This part doesn't include any charge that enhances hydrophobic. (Does not combine with water.

Now a positive ion can be brought only to electron-rich stations. We cannot say that this situation is forever the hydrophilic part.

A dual bond is an electron-rich situation. So the ion will be drawn to the dual bond place of a lipid.

2.

A conveyor that needs energy is active transport.

3.

The use of a membrane is to stop the particles and ions from passing crosswise it openly. So through the membrane, in an active carrier, we require input energy to transfer molecules beyond it.

Answer:

Where is the grahppppp?!!!!

Answer:

0.16 M.

Explanation:

Hello!

In this case, since the reaction can be determined as zeroth-order because of the units of M/s, we can write the rate law as:

[tex][X]=[X]_0-kt[/tex]

In such a way, since we need the initial concentration of X, we proceed as follows:

[tex][X]_0=[X]+kt[/tex]

So we plug in to obtain:

[tex][X]_0=0.096M+3.6x10^{-5}\frac{M}{s}*30.min*\frac{60s}{1min}[/tex]

[tex][X]_0=0.16M[/tex]

Best regards!

Answer:

Half-life of 150 years are those year that a radioactive element take to disintegrate to a half of it's original value.

I don't have graphical software

Answer: [tex]Fe^{2+}[/tex] is the reducing agent

Explanation:

Oxidation reaction : When there is an increase in oxidation state number.

Reduction reaction : when there is a decrease in oxidation state number.

[tex]5Fe^{2+}(aq)+MnO_4^-(aq)+8H^+(aq)\rightarrow 5Fe^{3+}(aq)+Mn^{2+}(aq) +4H_2O(l)[/tex]

Fe has undergone oxidation, as its oxidation state is changing from+2 to +3.

Mn has undergone reduction, as its oxidation state is changing from +7 to +2.

The chemical agent which itself get oxidized and reduce others is called reducing agent.  [tex]Fe^{2+}[/tex]  is a reducing agent.

The chemical agent which itself get reduced and oxidize others is called oxidizing agent. [tex]MnO_4^-[/tex] is an oxidizing agent.

.

Answer:

1)seismic 2) S-waves 3) outer core

Answer:the other comment is right

Explanation: