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
Ludmilka [50]
3 years ago
10

The black, granular material that fills a dry cell in a common flashlight (between the carbon rod and the zinc shell) is mangane

se dioxide, MnO2. The oxidation number of manganese in MnO2 is:
a. +2
b. -2
c. +4
d. -4
Chemistry
1 answer:
mestny [16]3 years ago
7 0

Answer: c. +4

Explanation:

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.  

Mn:25:1s^22s^22p^63s^23p^64s^23d^{5}

Mn^{4+}:21:1s^22s^22p^63s^23p^63d^1

O:8:1s^22s^22p^4

O^{2-}:10:1s^22s^22p^6

Here manganese is having an oxidation state of +4 called as  cation and oxygen forms an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged to give Mn_2O_4 which written in simplest whole number ratios to give neutral MnO_2

You might be interested in
Calculate the concentration of acetate ion in a buffer solution made from 2.00 mL of 0.50 M acetic acid and 8.00 mL of 0.50 sodi
Lelu [443]

Answer:

1 M

Explanation:

Equation of reaction is;

CH3COOH + CH3COONa -------------------> 2CH3COO^- + NaH

1 moles of each of the reactants react to give 2 moles of the acetate ion.

From the question, we have that 2.00 mL that is (2÷1000)L of 0.50 M acetic acid reacted with 8.00 mL that is (8/1000)L of 0.50 sodium acetate.

Then from equation, n = CV -------------------------------------------(1).

Where n= number of moles, V= volume, C= concentration.

Number of moles,n of acetic acid = 0.50M× 2/1000L.

n(acetic acid)= 0.001 moles.

Number of moles,n of sodium acetate= 0.50M ×(8/1000)L.

n(sodium acetate)= 0.004 moles.

0.001 moles of acetic acid react with 0.004 moles of Sodium acetate

Therefore, acetic acid is the limiting reagent.

One mole of acetic acid produces 2 moles of acetate ion.

0.001 mole of acetic acid produces= 0.002 moles of acetate ion.

Using the equation (1) that is, n= CV.

0.002= C× 2/1000

C= 0.002/0.002

C= 1 M

8 0
3 years ago
Std 10th
kondaur [170]

Answer:

zinc and lead or copper and tin

Explanation:

these elements react both as an acid as well as a base

5 0
3 years ago
Is 2AI + 3O2 = 2AI2O3 balanced or unbalanced
Rudik [331]
Balanced there are 2 Al, 6 oxygens on both sides.
7 0
3 years ago
Sodium carbonate (NaCO3) is sometimes used as a water-softening agent. Suppose that a worker prepares a 0.730 M solution of NaCO
sergey [27]

The molarity of a solution is the number of moles of a substance divided by the volume in liters prepared.

molarity=\frac{n}{V}, where n is number of moles and V is the volume in liters.

In order to calculate the mass of solute we need to convert the volume and molarity to moles

1.421 L solution \times\frac{0.0730 moles}{1 Lsolution}= 1.037 mol NaCO_3

Now that we have moles we use the relative formula mass of NaCO₃, We have 1 Na atom, 1 C atom and 3 O atoms, thus

M_r= (1\times 22.99) + (1\times 12.00) + (3\times 16.00)= 82.99g/mol

1.037 \times\frac{82.99g}{mol} = 86.1g

5 0
3 years ago
Read 2 more answers
El agua oxigenada se descompone rápidamente en agua y oxígeno cuando se le agrega una peueña cantidad de dióxido de manganeso, q
katovenus [111]

Answer:

IDK

Explanation:

I dont speak spanish

6 0
3 years ago
Other questions:
  • Define the term ionization energy. Choose one:
    11·1 answer
  • Which statement is true about the elements present in a pure substance?
    12·2 answers
  • A group of atoms that remain bonded together and behave as a single atom in a chemical reaction is
    15·1 answer
  • Which is the following summaries expresses the main points of the best passages
    6·2 answers
  • Suppose you set a glass of water in direct sunlight for 2 hours and measure its temperature every 10 min . What type of graph wo
    9·1 answer
  • In an experiment 25.0 mL of 0.100 M KI was diluted to 50.0 mL. Calculate the molarity of the diluted solution
    5·1 answer
  • What are the different chemical properties of the element Cobalt?
    10·1 answer
  • Is a 11 out of 15 on a chemistry quiz considered bad for a medium top student
    9·2 answers
  • Which gas law states that the volume of gas is directly proportional to its temperature
    15·2 answers
  • Definition<br> a visual representation of data that uses unconnected plotted points​
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!