I’m thinking it’s the last one but I’m not sure.

Answer:

I think it will option D hope it helps

If one DNA strand reads CCGTAATGCAT, the sequence of the complementary strand will be - b) GGCATTACGTA

So, DNA strand -                        C-C-G-T-A-A-T-G-C-A-T

Complementary DNA strand -  G-G-C-A-T-T-A-C-G-T-A

Thus, If one DNA strand reads CCGTAATGCAT, the sequence of the complementary strand will be - b) GGCATTACGTA

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Answer:

Xb = 0.59

Explanation:

Let's analyze the given data.

We have a total vapor pressure of 263 Torr for the mix of the two gases. And the individual vapour pressures for each gas is given, and it's 425 Torr for pentane and 151 Torr for hexane.

We are asked to determine the mole fraction of hexane. For practical purposes, we will label pentane as "a" while hexane would be "b". So, let's write the equations that we need to calculate this.

We know that the total pressure of a solution would be:

P = Pa + Pb    (1)

And we also know that these individual pressures are:

Pa = Xa * Pa°    (2)

Pb = Xb * Pb°    (3)

Where Pa° and Pb° are the vapour pressures of each gases.

The mole fractions (Xa and Xb), can be expressed, one in function of the other:

Xa + Xb = 1 -----> Xa = 1 - Xb     (4)

Now that we know this, we can replace (4) in (2), and then, (2) and (3) can be replaced in (1):

Pa = (1 - Xb)Pa°

P = (1 - Xb)Pa° + XbPb°      (5)

Replacing the given data, we have:

263 = (1 - Xb)*425 + 151Xb

Now solving for Xb, which is the mole fraction of hexane:

263 = 425 - 425Xb + 151Xb

263 - 425 = (-425 + 151)Xb

-162 = -274Xb

Xb = -162 / -274

Hope this helps

The molar concentration, often called molarity, describes how much of a substance (a solute) is present per unit of solvent. By definition, the molar concentration (M) is equal to the number of moles (n) of solute divided by the number of liters (the volume, or V) of the solution.

Here, your solute is potassium nitrate, or KNO3. You're given the mass of KNO3 (505 g), but you need to convert this quantity to moles before you can find the molarity. To go from mass to moles, simply divide the mass of the substance by its molar mass (given to you as 101.1 g/mol).

[tex]505 \text{ g KNO}_\text{3} \div 101.1 \text{ g KNO}_3/\text{mol KNO}_{3} = 4.995 \text{ mol KNO}_3[/tex]

Now that we have the moles of solute, we divide by the liters of solution. We're given the volume of solution in milliliters, so to convert to liters, simply divide by 1000 (1 L = 1000 mL, so 1 mL = 1/1000 mL). Our volume of solution is thus 0.250 L.

Finally, we can calculate the molar concentration of the KNO3 solution:

[tex]4.995 \text{ mol KNO}_{3 }\div 0.250 \text{ L} = 19.98 \text{ }\frac{\text{moles}}{\text{liters}}\text{ of KNO}_3[/tex]

But, we're told to round our answer to three sig figs. Thus, our rounded and final answer would be 20.0 moles/liters of KNO3.

Answer: There are [tex]6.926\times 10^{23}[/tex] molecules of glucose.

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

To calculate the molecules, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given molecules}}{\text {Avogadro's number}}[/tex]

[tex]1.15=\frac{x}{6.023\times 10^{23}}[/tex]

[tex]x=1.15\times 6.023\times 10^{23}=6.926\times 10^{23}[/tex]

Thus there are [tex]6.926\times 10^{23}[/tex] molecules of glucose.

Answer:

Zn + 2HCl -----> ZnCl2 + H2

Explanation:

Zinc chloride and hydrogen gas is formed

When zinc was combined with hydrochloric acid, hydrogen gas was evolved.

We know that a general property of metals is that they react with metals to evolve hydrogen gas. All metals that are above hydrogen in the activity series will undergo this reaction.

Hence, when hydrochloric acid and zinc were combined, the following reaction occured; Zn(s) + 2HCl(aq) -----> ZnCl2(aq) + H2(g). The colorless odorless gas evolved after this combination is hydrogen gas.

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Answer:

Kinetic

Explanation:

When the ball is falling towards the table, it has kinetic energy. This elastic potential energy is why the ball is able to bounce, or rebound. After the ball rebounds, the elastic potential energy is transformed into kinetic energy, but it will never possess as much kinetic energy as during its original fall.

Answer:

Explanation:

It has kinetic energy.

Hope it helped you.

Answer:

and birds can fly without wings es hora de vomer

Answer:

a period

Explanation:

Answer: The row of elements across the periodic table is called "periods".

Explanation:

In the Periodic Table, there are seven rows of elements, which is called periods.

458 g H₂SO₄

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

4.67 mol H₂SO₄

Step 2: Identify Conversions

[PT] Molar Mass of H - 1.01 g/mol

[PT] Molar Mass of S - 32.07 g/mol

[PT] Molar Mass of O - 16.00 g/mol

Molar Mass of H₂SO₄ - 2(1.01) + 32.07 + 4(16.00) = 98.09 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

458.08 g H₂SO₄ ≈ 458 g H₂SO₄

Answer:

neap tide

Explanation:

There are two different types of tides, which are the spring tide and the neap tide.

Neap tides are weak tides which occur when the gravitational forces of the sun and the moon are at right angles to each other with respect to the earth. Since the sun and moon are at right angles, it causes a difference between the low and high tide.

The spring tide are strong tides which occur when the moon, sun and earth are in straight line. The spring tide occur during full moon and new moon.

Answer:

Neap Tides  

The result is a neap tide. The same effect happens during third quarter. These occur during first and last quarter moons. The gravitational pull is not as strong.

Explanation:

the first answer is correct

Answer:

D all the above

Explanation:

Answer:

Answer:- Lions..

Explanation:

Hope you have got your answer..

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Answer:

8.397J/mol is the activation energy for the reaction

Explanation:

The graphical form of Arrhenius equation is:

ln k = -Ea/R*(1/T)+lnA

Where k is activation energy

Ea is activation energy

R is gas constant (8.314J/molK)

T is absolute temperature

And A is the pre-exponential factor.

The slope of the plot is -Ea/R:

-Ea/R = -1.01x10⁴K

-Ea/8.314J/molK = -1.01x10⁴K

Ea = -1.01x10⁴K*8.314J/molK

Ea = 8.397J/mol is the activation energy for the reaction

Answer:

Amount of heat required = 153.62 J

Explanation:

Given:

Mass = 163.45 g

∆Hvap = 43.3 kJ/mol

Molar mass C₂H₅OH = 46.07 g/mol

Find:

Amount of heat required

Computation:

Amount of heat required = Number of moles x Molar mass C₂H₅OH

Amount of heat required = [163.45/46.07][43.3]

Amount of heat required = 153.62 J

Answer:

A. True

Explanation:

The octane number is determined by comparing the characteristics of gasoline to isooctane (2,2,4-trimethylpentane) and heptane. The correct option is option A.

Basically, the higher the octane  number, the  greater the resistance of the gasoline to knocking.

Answer:

Option A is correct.

Option D is correct.

E is the correct answer

Explanation:

This a theoretical calorimetry problem that can be solved by thermodynamic concepts.

Our system is the unknown solid. If the temperature of water has increased, we can think, that the heat from the metal was absorbed by water, which is our surrounding. If in the analysis of the situation we use a calorimeter, knowing that it is an isolated system, which does not allow the entry or exit of heat, we can conclude that the heat released is equal to the heat absorbed.

In conclusion, the thermodynamic system is constituted by the chemical reaction. In this case, the surrounding is made up of water and the calorimeter itself.

Answer:

1.403x10²⁴ molecules

Explanation:

In order to calculate how many molecules of CO₂ are there in 102.5 g of the compound, we first convert grams to moles using its molar mass:

Now we convert moles into molecules using Avogadro's number:

This question is incomplete, the complete complete question is;

Coulomb's law for the energy of interaction between two charged ions;

E = Ke × q1q2/r

Coulomb's constant Ke = 2.31 × 10⁻²⁸ J.m.

Calculate the bond energy in the ionic compound NaCl if the bond length is 2.36 × 10⁻¹⁰m

Answer:

the bond energy is -9.788 × 10⁻¹⁹ J

Explanation:

Given the data in the question;

Ke = 2.31 × 10⁻²⁸ J.m which is the same as; Ke = 2.31 × 10⁻²⁸ Nm L/c²

ionic compound NaCl;

q1 = charge on Na in NaCl = Na⁺ = + 1C

q2 = charge on Cl in NaCl = Cl⁻ = - 1C

given that bond length r is 2.36 × 10⁻¹⁰m

E = Ke × q1q2/r

we substitute

E = 2.31 × 10⁻²⁸ × (+1 × -1) / 2.36 × 10⁻¹⁰

E = -2.31 × 10⁻²⁸ / 2.36 × 10⁻¹⁰

E = -9.788 × 10⁻¹⁹ J    { The negative sign means Attraction in ions }

Therefore, the bond energy is -9.788 × 10⁻¹⁹ J

Answer:

Yes

Explanation:

Answer:

Lithium oxide, Li₂O.  

Explanation:

Hello!  

In this case, according to the given amounts, it is possible to write down the chemical reaction as shown below:

[tex]M_2O+H_2\rightarrow 2M+H_2O[/tex]  

Which means that the metallic oxide has the following formula: M₂O. Next, we can set up the following proportional factors according to the chemical reaction:

Thus, we perform the operations in order to obtain:

[tex]\frac{10X}{(2X+16)}=2.32[/tex]  

So we solve for x as shown below:

[tex]10X=2.32(2X+16)\\\\10X=4.64X+37.12\\\\X=\frac{37.12}{10-4.64}\\\\X= 6.93g/mol[/tex]  

Whose molar mass corresponds to lithium, and therefore, the metallic oxide is lithium oxide, Li₂O.  

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Answer:

When two or more atoms chemically bond with each other, the resultant chemical structure is a molecule. The familiar water molecule, H2O, consists of two hydrogen atoms and one oxygen atom; these bond together to form water,  irdk but it's either C or D

Explanation:

hope this helps have a good rest of your day :) ❤

Answer:

Independent

Explanation:

Independent Variable is the volume of the object. Dependent Variable is the mass of the object. So it

Answer:

See answer below

Explanation:

Let's write the equation again:

H₂ + O₂ ---------> H₂O

Now that we have written the equation, let's solve the exercise:

1. In this case, we first need to make a difference between atom and molecule. An atom is just a single element, a molecule it's when you have more than 1 element in a compound.

Knowing this, we have the H₂. In this case we only have one element, Hydrogen. However, as you can see in the expression, we have a number 2 as a subscript. The number 2 means that the hydrogen it's not alone, we do not have one hydrogen, we have two hydrogens, therefore, it becomes a molecule. Now, This molecule, according to the number 2 as subscript, means that the molecule of hydrogen have 2 atoms of hydrogens, and this formed the molecule, therefore, there are 2 atoms of hydrogens in H₂.

2. Following the same explanation of above, but using oxygen, we have the same thing, so, in a molecule of O₂, we have 2 atoms of oxygen.

3. The molecule of water is composed of Hydrogen and oxygen. As you can see, in this case we have 2 hydrogen and 1 oxygen, therefore, in 1 molecule of water, there are 1 atom of oxygen and 2 atoms of hydrogen.

4. The subscript, as you may know now, tell us the number of atoms that you have in a molecule or compound. This number also means, in different compounds the oxidation state of the atoms that conform the molecule.

5. No, the equation is not balanced, because we do not have the same number of oxygen on the side of the products. We need to balance that. As the oxygen is unbalanced, we just need to put numbers as coefficients, behind the molecule. This number will multiply the number of atoms of the referred molecule. So, doing this with the water on the products to equal the number of oxygen, we have:

H₂ + O₂ ---------> 2H₂O

But this 2, unbalance at the same time the number of hydrogens. We now have 4 hydrogens in the product, so, to balance this, we put a 2 on the reactants:

2H₂ + O₂ ---------> 2H₂O

Now the reaction is balanced.

Hope this helps

Answer:

  58.0 g/mol

Explanation:

At STP, one mole occupies 22.4 liters. One mole of the hydrocarbon would have a mass of ...

  (2.59 g/L)(22.4 L/mol) ≈ 58.0 g/mol

Answer:

Answer: single replacement reaction, [tex]3Sr+2Al(ClO_3)_3\rightarrow 3Sr(ClO_3)_2+2Al[/tex]

Explanation:

A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.

A general single displacement reaction can be represented as :

[tex]XY+Z\rightarrow XZ+Y[/tex]

As strontium metal is added to aluminum chlorate , strontium being more reactive than aluminium, displaces aluminium atom its salt solution and lead to formation of strontium  chlorate and aluminum metal.

[tex]3Sr+2Al(ClO_3)_3\rightarrow 3Sr(ClO_3)_2+2Al[/tex]

Answer:

Formulas

3.2 Determining Empirical and Molecular Formulas

Learning Objectives

By the end of this section, you will be able to:

Compute the percent composition of a compound

Determine the empirical formula of a compound

Determine the molecular formula of a compound

The previous section discussed the relationship between the bulk mass of a substance and the number of atoms or molecules it contains (moles). Given the chemical formula of the substance, one may determine the amount of the substance (moles) from its mass, and vice versa. But what if the chemical formula of a substance is unknown? In this section, these same principles will be applied to derive the chemical formulas of unknown substances from experimental mass measurements.

Percent Composition

The elemental makeup of a compound defines its chemical identity, and chemical formulas are the most succinct way of representing this elemental makeup. When a compound’s formula is unknown, measuring the mass of each of its constituent elements is often the first step in the process of determining the formula experimentally. The results of these measurements permit the calculation of the compound’s percent composition, defined as the percentage by mass of each element in the compound. For example, consider a gaseous compound composed solely of carbon and hydrogen. The percent composition of this compound could be represented as follows:

%H=mass Hmass compound×100%

%C=mass Cmass compound×100%

If analysis of a 10.0-g sample of this gas showed it to contain 2.5 g H and 7.5 g C, the percent composition would be calculated to be 25% H and 75% C:

%H=2.5g H10.0g compound×100%=25%

%C=7.5g C10.0g compound×100%=75%

EXAMPLE 3.9

Calculation of Percent Composition

Analysis of a 12.04-g sample of a liquid compound composed of carbon, hydrogen, and nitrogen showed it to contain 7.34 g C, 1.85 g H, and 2.85 g N. What is the percent composition of this compound?

Solution

To calculate percent composition, divide the experimentally derived mass of each element by the overall mass of the compound, and then convert to a percentage:

%C=7.34g C12.04g compound×100%=61.0%%H=1.85g H12.04g compound×100%=15.4%%N=2.85g N12.04g compound×100%=23.7%

The analysis results indicate that the compound is 61.0% C, 15.4% H, and 23.7% N by mass.

Check Your Learning

A 24.81-g sample of a gaseous compound containing only carbon, oxygen, and chlorine is determined to contain 3.01 g C, 4.00 g O, and 17.81 g Cl. What is this compound’s percent composition?

ANSWER:

12.1% C, 16.1% O, 71.8% Cl

Determining Percent Composition from Molecular or Empirical Formulas

Percent composition is also useful for evaluating the relative abundance of a given element in different compounds of known formulas. As one example, consider the common nitrogen-containing fertilizers ammonia (NH3), ammonium nitrate (NH4NO3), and urea (CH4N2O). The element nitrogen is the active ingredient for agricultural purposes, so the mass percentage of nitrogen in the compound is a practical and economic concern for consumers choosing among these fertilizers. For these sorts of applications, the percent composition of a compound is easily derived from its formula mass and the atomic masses of its constituent elements. A molecule of NH3 contains one N atom weighing 14.01 amu and three H atoms weighing a total of (3 × 1.008 amu) = 3.024 amu. The formula mass of ammonia is therefore (14.01 amu + 3.024 amu) = 17.03 amu, and its percent composition is:

%N=14.01amu N17.03amuNH3×100%=82.27%%H=3.024amu H17.03amuNH3×100%=17.76%

This same approach may be taken considering a pair of molecules, a dozen molecules, or a mole of molecules, etc. The latter amount is most convenient and would simply involve the use of molar masses instead of atomic and formula masses, as demonstrated Example 3.10. As long as the molecular or empirical formula of the compound in question is known, the percent composition may be derived from the atomic or molar masses of the

Answer:

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.

Explanation:

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