Hydrogen bonds can be found between molecules of which substance?

Why is respiration an exothermic reaction?

Degger [83]

Answer: A large amount of energy is released into the surroundings.

Explanation:-

Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and $\Delta H$ which is difference between energy of products and energy of reactants come out to be positive.

Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and $\Delta H$ which is difference between energy of products and energy of reactants comes out to be negative.

Thus a reaction in which large amount of energy is released is categorized as exothermic reaction and thus respiration is also a exothermic reaction.

7 0

3 years ago

Arrange the ions N3-, O2-, Mg2 , Na , and F- in order of increasing ionic radius, starting with the smallest first. Arrange the

Bond [772]

Answer:

Order of increasing ionic radius starting from the smallest is

Mg2+ < Na+ < F- < O2- < N3-

Explanation:

Ionic radius is the distance between the nucleus and the electrons in the outermost shell of an ion. In the ions given about, it can be deducted that they all have the same number of electrons and are said to be isoelectronic. This shows us that they all have the same electrons and we can only seperate them by checking the respective charges on the ions. A more positive charge will have a smaller radius while a more negative will have a larger radius. This is because when an atom loses an electron and form a cation (+), the remaining electrons move closer to the nucleus and hence a smaller radius of the atom occurs. But when an atom gains n electron,it forms anion (-), the new electron leads to the shielding of the remaining electrons from the nucleus and a large radius of the atom occurs.

So therefore, the above ions all have 10 electrons in their shells and magnesium with atomic number 12 and having lost 2 electrons to become positively charge has the smallest radius compared to others.

Mg2+ = 12 protons, 10 electrons

Na+ = 11 protons, 10 electrons

F- = 9 protons, 10 electrons

O2- = 8 protons, 10 electrons

N3- = 7 protons, 10 electrons

N3- has the largest ionic radius and Mg2+ has the lowest ionic radius.

The order is thus, Mg2+ , Na+, F-, O2-, N3-

6 0

4 years ago

What do navigators need to consider when plotting a course?

Vaselesa [24]

1.) scale of the chart
2.) Notes of the chart
3.) chart symbols
4.) chart corrections
5.) GPS positions
6.) radar fixes

7.) Visual fixtures and position circle and position line

8 0

3 years ago

Suppose now that you wanted to determine the density of a small crystal to confirm that it is sulfur. From the literature, you k

ivolga24 [154]

Answer:

Mix 11.73 mL of CHCl₃ and 8.27 mL of CHBr₃

Explanation:

To begin, it seems your question lacks the name of the pure samples that will be mixed to prepare the liquid mixture. The names are not necessary, as the numerical values are there. However, an internet search tells me they are CHCl₃ (d=1.492g/mL) and CHBr₃ (d=2.890 g/mL).

The mixture has a density of 2.07 g/mL, so <u>20 mL of the mixture would weigh</u>:

20 mL * 2.07 g/mL = 41.4 g

Let X be the volume of CHCl₃ and Y the volume of CHBr₃:

X + Y = 20 mL

The mass of CHCl₃ and CHBr₃ combined have to be equal to the mass of the mixture. We can write that equation using the volume of the samples and their density:

X * 1.492 + Y * 2.890 = 41.4 g

So now we have a system of two equations and two unknowns, we use algebra to solve it:

1. Express Y in terms of X:

X + Y = 20

Y = 20 - X

2. Replace Y in the second equation:

X * 1.492 + Y * 2.890 = 41.4

1.492*X + 2.890*(20-X) = 41.4

3. Solve for X:

1.492*X + 57.8 - 2.890*X = 41.4

1.398*X = 16.4

X = 11.73 mL

4. Using the now known value of X, solve for Y:

X + Y = 20

11.73 + Y = 20

Y = 8.27 mL

So, to prepare the liquid mixture we would mix 8.27 mL of CHBr₃ and 11.73 mL of CHCl₃.

7 0

4 years ago

Group 2 in the periodic table contains the elements beryllium (be), magnesium (mg), calcium (ca), strontium (sr), barium (ba), a

Artist 52 [7]

Lose 2 electron to form 2+

6 0

3 years ago