All categories

3 years ago

A negative ion is (larger/smaller) than its parent atom. Why?

Chemistry

1 answer:

Kay [80]3 years ago

5 0

Answer:

When an atom attracts extra electrons it becomes a negative ion. The negative ion is larger than the original atom. The positive nucleus remains the same, with the same attractive force. However, this attractive force is now pulling on more electrons and therefore has less effect.

Positive ions are formed by removing one or more electrons from the outermost region of the atom. The opposite is true of negative ions. When electrons are added to form an anion, the increased electron-electron repulsions cause the electrons to spread out more in space. Thus, anions are larger than their parent atoms.

You might be interested in

A titration of 25.0 mL of a solution of the weak base aniline, C6H5NH2, requires 25.67 mL of 0.175 M HCl to reach the equivalenc

Lorico [155]

Answer:

a. 0.180M of C₆H₅NH₂

b. 0.0887M C₆H₅NH₃⁺

c. pH = 2.83

Explanation:

a. Based in the chemical equation:

C₆H₅NH₂(aq) + HCl(aq) → C₆H₅NH₃⁺(aq) + Cl⁻(aq)

<em>1 mole of aniline reacts per mole of HCl</em>

Moles required to reach equivalence point are:

Moles HCl = 0.02567L ₓ (0.175mol / L) = 4.492x10⁻³ moles HCl = moles C₆H₅NH₂

As the original solution had a volume of 25.0mL = 0.0250L:

4.492x10⁻³ moles C₆H₅NH₂ / 0.0250L = 0.180M of C₆H₅NH₂

b. At equivalence point, moles of C₆H₅NH₃⁺ are equal to initial moles of C₆H₅NH₂, that is 4.492x10⁻³ moles

But now, volume is 25.0mL + 25.67mL = 50.67mL = 0.05067L. Thus, molar concentration of C₆H₅NH₃⁺ is:

[C₆H₅NH₃⁺] = 4.492x10⁻³ moles / 0.05067L = 0.0887M C₆H₅NH₃⁺

c. At equivalence point you have just 0.0887M C₆H₅NH₃⁺ in solution. C₆H₅NH₃⁺ has as equilibrium in water:

C₆H₅NH₃⁺(aq) + H₂O(l) → C₆H₅NH₂ + H₃O⁺

Where Ka = Kw / Kb = 1x10⁻¹⁴ / 4.0x10⁻¹⁰ =

When the system reaches equilibrium, molar concentrations are:

[C₆H₅NH₃⁺] = 0.0887M - X

[C₆H₅NH₂] = X

[H₃O⁺] = X

Replacing in Ka formula:

2.5x10⁻⁵ = [X] [X] / [0.0887M - X]

2.2175x10⁻⁶ - 2.5x10⁻⁵X = X²

0 = X² + 2.5x10⁻⁵X - 2.2175x10⁻⁶

Solving for X:

X = -0.0015 → False solution. There is no negative concentrations.

X = 0.001477 → Right solution.

As [H₃O⁺] = X, [H₃O⁺] = 0.001477

Knowing pH = -log [H₃O⁺]

pH = -log 0.001477

7 0

2 years ago

What happens to a line when the y-intercept is changed? Check all that apply.

tamaranim1 [39]

Answer:

As the y-intercept increases, the graph of the line shifts up;

As the y-intercept decreases, the graph of the line shifts down

Explanation:

There are two ways to think about this problem. The first way would be the graphical approach:

if we only change the y-intercept, this means we keep the same slope;
y-axis is the vertical axis;
if we change the point at which the line crosses the y-axis, we either shift it upward for a higher y-intercept or downward for a lower y-intercept.

Now, thinking algebraically, a line has the following equation in a general form:

$y = mx + b$

The y-intercept is essentially obtained when x = 0, then:

y = b:

if we increase b value, the y value increases, so the graph shifts upward;
if we decrease b value, the y value decreases, so the graph shifts downward.

5 0

3 years ago

temperature is the transfer of thermal energy from one object to another. Please select the best answer from the choices provide

Hunter-Best [27]

The statement above is FALSE.

Temperature is the degree of coldness or hotness of a body while heat transfer is the transfer of thermal energy from one object to another object. Temperature tells us how cold or hot a body is and it can be measured in Celsius, Kelvin or Fahrenheit. The thermometer is the instrument that is used in the measurement of temperature. Change in temperature is an important indicator that is used in various ways in humans and external systems.

5 0

3 years ago

How does the periodic table help I’m predicting the formula of a stable ionic compound

WITCHER [35]

The answer is B on edge

4 0

3 years ago

What season does the sourtther hempishere experience when it is away from the sun?

kakasveta [241]

I believe Winter is <span>your answer.</span>

4 0

3 years ago