1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
djyliett [7]
2 years ago
9

WW

Chemistry
1 answer:
SVETLANKA909090 [29]2 years ago
4 0
11 is the answer hope that helps
You might be interested in
What is the meaning of the following metric prefixes kilo,deco,centi,milli,micro and nono
BigorU [14]
Kilo: a prefix used on metric units to indicate a multiple of 1000. For example 1kg = 1000 g
4 0
3 years ago
What is an ion? what is a valence electron? how is an ion formed?
Anna35 [415]

Answer:

Ions are formed when atoms lose or gain electrons in order to fulfill the octet rule and have full outer valence electron shells. When they lose electrons, they become positively charged and are named cations. When they gain electrons, they are negatively charged and are named anions.

Explanation:

8 0
3 years ago
Read 2 more answers
What is the pH at the equivalence point in the titration of a 25.7 mL sample of a 0.370 M aqueous nitrous acid solution with a 0
expeople1 [14]

Answer:

pH = 8.24

Explanation:

Nitrous acid (HNO₂) reacts with KOH, thus:

HNO₂ + KOH → KNO₂ + H₂O

Moles of HNO₂ are:

0.0257mL ₓ (0.370mol / L) = 0.00951moles.

In equivalence point, the complete moles of nitrous acid reacts with KOH producing potassium nitrite. There are needed:

0.00951mol ₓ (1L / 0.491mol) = 0.01937L ≡ 19.4mL of 0.491M KOH to reach equivalence point.

Total volume in equivalence point is: 19.4mL + 25.7mL = <em>45.1mL</em>

Potassium nitrite is in equilibrium with water, thus:

NO₂⁻ + H₂O ⇄ HNO₂ + OH⁻

Where equilibrium constant, Kb, is defined as:

Kb = 1.41x10⁻¹¹ = \frac{[OH^-][HNO_2]}{[NO_2]}

In equilibrium, molarity of each compound are:

[NO₂⁻]: 0.00951mol/0.00451L - X = 0.211M - X

[HNO₂]: X

[OH⁻]: X

<em>Where X is reaction coordinate</em>

Replacing in Kb:

1.41x10⁻¹¹ = \frac{[X][X]}{[0.211 -X]}

0 = X² + 1.41x10⁻¹¹X - 2.97x10⁻¹²

Solving for X:

X = -1.72x10⁻⁶ <em>FALSE ANSWER. There is no negative concentrations.</em>

X = 1.72x10⁻⁶. <em>Right answer.</em>

That means:

[OH⁻]: 1.72x10⁻⁶M

As pOH is -log [OH⁻] and pH = 14-pOH:

pOH = 5.76; <em>pH = 8.24</em>

3 0
3 years ago
Q 3.6: calculate the number of po43- ions present in 23.7 g of ca3(po4)2.
malfutka [58]
Moles of ca3(po4)2 = 23.7 / 310.17 =  0.076

moles of (PO4)3- = 0.076 x 2 = 0.152

now, no. of ions = 0.152 x 6.022 x 10^{23}

                          =  9.2 x 10^{22}
6 0
3 years ago
Read 2 more answers
Given the balanced equation representing a reaction at 101.3 kPa and 298 K:
ser-zykov [4K]
Answer (4)

Endothermic processes: are those in which occurs the absorption of heat.
the change of enthalpy (ΔH) is greater <span>than zero.
</span>
hope this helps!
8 0
3 years ago
Other questions:
  • A substance that forms a vapor is generally in what physical state at room temperature? solid gas liquid or solid liquid
    13·2 answers
  • Assuming ideal solution behavior, what is the freezing point of a solution of 9.04 g of I2 in 75.5 g of benzene?
    5·1 answer
  • The elements helium and xenon are all part of the same ​
    14·1 answer
  • Childrens chewable Tylenol contains 80.mg of acetaminophen per tablet. If the recommended dosage is 10 .mg/kg , calculate the nu
    14·1 answer
  • Is electrolysis of water an example of a chemical reaction? Why or why not?
    9·1 answer
  • When DNA is replicated, it is necessary for the two strands to "unzip" temporarily. Choose which bonding type is most appropriat
    9·1 answer
  • Which of the following is a pure substance?<br>Air<br>Blood<br>Copper<br>Wood​
    8·2 answers
  • Can y'all help me on number 10❤️
    5·1 answer
  • Describe the neutral signaling pathway
    14·1 answer
  • RESEARCHING ENERGY TRANSFORMATIONS
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!