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konstantin123 [22]

3 years ago

9

a 2-kg bowling ball is 2.5 meter off the ground on a post when it falls just before it reachers the ground it is traveling 7 m/s

.Assuming that there is no air resistance wich statement is true

1 answer:

nikklg [1K]3 years ago

8 0

The answer to your question is the mechanical energy is conserved.

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How does the appearance of<br> the protist differ from that of the onion sample?

lana [24]

The appearance of the protist differ from that of the onion sample due to the presence of motile structures.

<h3>What is a Protist?</h3>

This is an eukaryote which could be unicellular or multicellular and examples include protozoa etc.

The major difference between a protist and onion sample is that protists have motile structures such as flagella, cilia etc while plant cells such as onions don't have.

Read more about Protist here brainly.com/question/2169979

#SPJ1

8 0

2 years ago

A buffer can be prepared by mixing two solutions. Determine if each of the following mixtures will result in a buffer solution o

GenaCL600 [577]

Answer:

The answers are in the explanation

Explanation:

A buffer is the mixture of a weak acid with its conjugate base or vice versa. Thus:

<em>1)</em> Mixing 100.0 mL of 0.1 M HF with 100.0 mL of 0.05 M mol KF. <em>Will </em>result in a buffer because HF is a weak acid and KF is its conjugate base.

<em>2)</em> Mixing 100.0 mL of 0.1 M NH₃ with 100.0 mL of 0.1 M NH₄Br. <em>Will not </em>result in a buffer because NH₃ is a strong base.

<em>3) </em>Mixing 100.0 mL of 0.1 M HCN with 100.0 mL of 0.05 M KOH. <em>Will </em>result in a buffer because HCN is a weak acid and its reaction with KOH will produce CN⁻ that is its conjugate base.

<em>4)</em> Mixing 100.0 mL of 0.1 M HCl with 100.0 mL of 0.1 M KCl <em>Will not </em>result in a buffer because HCl is a strong acid.

<em>5)</em> Mixing 100.0 mL of 0.1 M HCN with 100.0 mL of 0.1 M KOH <em>Will not </em>result in a buffer because each HCN will react with KOH producing CN⁻, that means that you will have just CN⁻ (Conjugate base) without HCN (Weak acid).

I hope it helps!

6 0

3 years ago

const2013 [10]

Answer:

$\large \boxed{\text{-1276 kJ/mol}}$

Explanation:

You calculate the energy required to break all the bonds in the reactants.

Then you subtract the energy needed to break all the bonds in the products.

CH₃CH₂OH + 3O₂ ⟶ 2CO₂ + 3H₂O

Bonds: 5C-H 1C-C 1C-O 1O-H 3O=O 4C=O 6O-H

D/kJ·mol⁻¹: 413 347 358 467 495 799 467

$\Delta H = \sum{D_{\text{reactants}}} - \sum{D_{\text{products}}}\\\sum{D_{\text{reactants}}} = 5 \times 413 + 1 \times 347 + 1 \times 358 + 1 \times 467 + 3 \times 495 = 3237 + 1485\\=\text{4722 kJ}\\\sum{D_{\text{products}}} = 4 \times 799 + 6 \times 467 =3196 + 2802 = \text{5998 kJ}\\\Delta H = 4722 - 5998= \textbf{-1276 kJ} \\ \text{The overall energy change is $\large \boxed{\textbf{-1276 kJ/mol}}$}.$

6 0

3 years ago

The chemical symbol of several elements are given below. Determine the atomic number of each element. Chemical Atomic Number Sym

spayn [35]

<u>Explanation:</u>

Atomic number is defined as the number of protons or electrons that are present in a neutral atom.

Atomic number = number of protons = number of electrons

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

The isotopic representation of an atom is: $_Z^A\textrm{X}$

where,

Z = Atomic number of the atom

A = Mass number of the atom

X = Symbol of the atom

<u>For A:</u>

1) Fe

The atom given to us is iron. It is present in Group 8 and period 4 of the periodic table. The atomic number of iron is 26

2) Be

The atom given to us is beryllium. It is present in Group 2 and period 2 of the periodic table. The atomic number of beryllium is 4

3) Kr

The atom given to us is krypton. It is present in Group 18 and period 4 of the periodic table. The atomic number of iron is 36

<u>For B:</u>

1) $_{24}^{53}\textrm{Cr}$

Atomic number = Number of protons = Number of electrons = 24

Mass number = 53

Number of neutrons = 53 - 24 = 29

The number of protons, electrons and neutrons for the given element are 24, 24 and 29 respectively

2) $_{44}^{103}\textrm{Ru}$

Atomic number = Number of protons = Number of electrons = 44

Mass number = 103

Number of neutrons = 103 - 44 = 59

The number of protons, electrons and neutrons for the given element are 44, 44 and 59 respectively

3) $_{30}^{67}\textrm{Zn}$

Atomic number = Number of protons = Number of electrons = 30

Mass number = 67

Number of neutrons = 67 - 30 = 37

The number of protons, electrons and neutrons for the given element are 30, 30 and 37 respectively

<u>For C:</u>

1) Atomic number = 14; Mass number = 28

The element having atomic number '14' is Silicon

The isotopic symbol of the element is $_{14}^{28}\textrm{Si}$

The symbol of the element is 'Si'

2) Atomic number = 18; Mass number = 40

The element having atomic number '18' is Argon

The isotopic symbol of the element is $_{18}^{40}\textrm{Ar}$

The symbol of the element is 'Ar'

3) Atomic number = 19; Mass number = 39

The element having atomic number '19' is Potassium

The isotopic symbol of the element is $_{19}^{39}\textrm{K}$

The symbol of the element is 'K'

5 0

3 years ago

Could acetic acid be used in the esterification, instead of acetyl chloride? Why or why not?

Vanyuwa [196]

Answer:

Yes, acetic acid could be used, but it would not be as effective as acetyl chloride or acetic anhydride. ... However, the acetic anhydride would still be reacting with an alcohol, so nothing changes in that respect. Also, the reaction would need to be done in basic solution.

4 0

3 years ago