Choose all the answers that apply.

What does the cardiovascular system do?

transports oxygen and carbon dioxide for the respiratory system
carries nutrients for the digestive system
works with the immune system to fight infection
carries hormones for the endocrine system
sends nerve impulses to the brain and spinal cord

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:

Independent

Explanation:

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

Answer:

no, and next time take it right

Explanation:

Answer:

44.45 g of tetrahydrofuran.

Explanation:

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

Volume of tetrahydrofuran = 50 mL

Density of tetrahydrofuran = 0.889 g/mL

Mass of tetrahydrofuran =?

Density of a substance is simply defined as the mass of the substance per unit volume of the substance. Mathematically, density is expressed as shown below:

Density = mass / volume

With the above formula, we shall determine the mass of tetrahydrofuran needed. This can be obtained as follow:

Volume of tetrahydrofuran = 50 mL

Density of tetrahydrofuran = 0.889 g/mL

Mass of tetrahydrofuran =?

Density = mass / volume

0.889 = mass / 50

Cross multiply

Mass = 0.889 × 50

Mass of tetrahydrofuran = 44.45 g

Therefore, the student should weigh out 44.45 g of tetrahydrofuran.

Answer: Thermal Equilibrium

Explanation:

Answer:

temperature  

Explanation:

I think that's it i'm sorry if i'm wrong

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:

You need to add 0.243g of NaOH to raise the temperature back to 16.2°C

Explanation:

Using the equation:

Q = C*m*ΔT

Where Q is heat

C is specific heat

m is mass

and ΔT is change in temperature

We can find the heat required to increase the temperature of the solution back to 16.2°C:

Assuming specific heat of the solution of water + K2SO4 = Specific heat of water:

C = 4.184J/g°C

m = 1.56g + 6.00g = 7.56g

ΔT = 16.2°C - 7.70°C = 8.50°C

Q = 4.184J/g°C * 7.56g * 8.50°C

Q = 268.86J = 0.269kJ of heat are required

As this heat is obtained from the dissolution of NaOH:

0.269kJ * (1mol NaOH / 44.3kJ) = 0.00607 moles of NaOH are required

In grams -Molar mass NaOH: 40g/mol-:

0.00607 moles NaOH * (40g / mol) =

Answer:

See explanation

Explanation:

The solar system consists of the sun at the core surrounded by all the planets in their proper order. Similarly, the Bohr model of the atom upholds Rutherford's planetary model in which the atom was said to have a positive core surrounded by electrons moving in orbits just as the planets orbit round the sun.

The difference between the two models is that electrons are able to move from one energy level to another. This assumption violates the principles of the solar system because the position of the planets are fixed in their orbits.

The theoretical basis behind this assumption is that each spectral line is produced by the transition of electrons from one energy level to another.

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:

I hope this helps :) Thank you. Plz mark brainliest.

Answer:

1)40n

2)25n

Explanation:

subtract the numbers if its on the opposite sides and add if its on same side

thank u hope it helps

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: soaps are a sodium or potassium salts of long chain fatty acids.when triglycerides in fat/oil react with aqueous NaOH or KOH,they are converted into soap and glycerol.This is called alkaline hydrolysis of esters.Since this reaction leads to formation of soap, it is called the saponification process.

Explanation:

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

Answer: 1and 4

Explanation: iron is an element not an alloy. An ionic lattice is not bonded covalently.

Answer:

323.22 ml

Explanation:

Given that :

Diameter, d = 6.8cm

Height, h = 8.9cm

V = arh

Recall :

Volume, V = πr²h

Radius, r = diameter / 2 = 6.8 / 2 = 3.4cm

V = π * 3.4^2 * 8.9

V = 323.21961 cm³

Recall:

1ml = 1cm³

Hence,

323.21961 cm³ = 323.21961 ml

Volume = 323.22 ml

Answer:

Kp = Kc (RT) ^(-2)

Explanation:

For the reaction;

N2 (g) + 3H2 ⇄ 2NH3(g)

We can write;

Kc = [NH3]^2/[N2] [H2]^3

But

Kp = pNH3^2/pN2 . PH2^3

To convert from Kc to Kp

Kp = Kc (RT) ^Δn

where Δn is the change in number of moles going from reactants

to products.

For this reaction;

Δn = 2- (3+1) = -2

Kp = Kc (RT) ^(-2)

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:

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:

Answer:

the lattice constant is 0.270 inches

Explanation:

Given the data in the question;

For FCC lattice;

a = b = c, ∝ = β = α = 90°

from the image below;

AC = 0.19 + 0.19/2 + 0.19/2 + 2(0.001) inch

AC = 0.19 + 0.095 + 0.095 + 0.002

AC = 0.382 inches

Now using Pythagoras theorem

AC² = AB² + BC²

since a = b = c

AC² = a² + a²

(0.382)² = 2a²

2a² = 0.145924

a² = 0.145924 / 2

a² = 0.072962

a = √0.072962

a =  0.27011 ≈ 0.270 inches

Therefore, the lattice constant is 0.270 inches

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:

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:

4.82 moles of Ag.

Explanation:

We'll begin by calculating the number of mole in 450.98 g of Cu(NO₃)₂. This can be obtained as follow:

Molar mass of Cu(NO₃)₂ = 63.5 + 2[14 + (16×3)]

= 63.5 + 2[14 + 48]

= 63.5 + 2[62]

= 63.5 + 124

= 187.5 g/mol

Mass of Cu(NO₃)₂ = 450.98 g

Mole of Cu(NO₃)₂ =?

Mole = mass /Molar mass

Mole of Cu(NO₃)₂ = 450.98 / 187.5

Mole of Cu(NO₃)₂ = 2.41 moles

Next, we shall determine the number of mole of Cu needed to produce 450.98 g (i.e 2.41 moles) of Cu(NO₃)₂. This can be obtained as follow:

Cu + 2AgNO₃ —> Cu(NO₃)₂ + 2Ag

From the balanced equation above,

1 mole of Cu reacted to produce 1 mole of Cu(NO₃)₂.

Therefore, 2.41 moles of Cu will also react to produce 2.41 moles of Cu(NO₃)₂.

Thus, 2.41 moles of Cu is needed for the reaction.

Finally, we shall determine the number of mole of Ag produced from the reaction. This can be obtained as follow:

From the balanced equation above,

1 mole of Cu reacted to produce 2 moles of Ag.

Therefore, 2.41 moles of Cu will react to produce = 2× 2.41 = 4.82 moles of Ag.

Thus, 4.82 moles of Ag were obtained from the reaction.

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

Learn more:

https://brainly.com/question/3372278

Answer:

1. 0.097 s

2. 0.420 M

Explanation:

To solve both questions we'll use the formula:

[A]ₓ = [A]₀ - kt

Where [A]ₓ is the concentration of A at a given time; and [A]₀ is the initial concentration.

1) We input the data given by the problem:

0.167 M = 0.700 M - 5.48 M/s * t

And solve for t:

t = 0.097 s

2) We input the new data:

[A]ₓ = 0.500 M - 0.361 M/s * 0.220 s

and solve for [A]ₓ:

[A]ₓ = 0.420 M

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:

It uses this term to represent the economic use of land and nature, with minimal degradation and maximum environmental preservation.

Explanation:

Capitalism is an economic system that promotes the maximum economic exploitation of terrestrial resources. It is common for this exploitation to be strongly associated with environmental degradation, destruction of natural habitats, deforestation and death of fauna and flora. With this, we can consider that capitalism is one of the main formulators of environmental degradation, however many professionals have considered the term "capitalism mated with conservation," where terrestrial resources are exploited consciously and with the objective of reducing degradation to the maximum. environmental impact and maximize conservation.