Which of these is the best evidence that a chemical reactions occurs when coal burns?

Balance the following equations:

Brilliant_brown [7]

Answer:

1) 0 C2H4O2 + 0 O2 -> 0 CO2 + 0 H2O (balanced)

2) V2O5 + CaS -> CaO + V2S5

just additional info: V2O5 is divanadium pentaoxide

LHS (Left hand side)

V: 2

O: 5

Ca: 1

S: 1 x 5 [to balance with the right hand side of the equation]

RHS (Right hand side)

V: 2

O: 1 x 5 [to balance with the left hand side of the equation]

Ca: 1

S: 5

When you balance any elements, you have to balance the whole chemical compound.

Thus,

V2O5 + 5 CaS -> 5 CaO + V2S5

LHS CHECK:

V: 2

O: 5

Ca: 5

S: 5

RHS CHECK:

V: 2

O: 5

Ca: 5

S: 5

3) S8 + O2 -> SO2

LHS:

S: 8

O: 2

RHS:

S: 1 x 8 [to balance with LHS]

O: 2

When you balance any elements, you have to balance the whole chemical compound.

S8 + O2 -> 8 SO2

When we add 8 to the RHS, it gives us 8S, 16 O.

In order to balance that into the RHS, I need to multiply the O2 by 8, which will give 8(O2) = 16 O particles.

Therefore, S8 + 8 O2 -> 8 SO2 is the final answer for (3).

6 0

3 years ago

Which of the following statements are true about metallic bonds?

Alborosie

Answer:

B. They bond identical atoms together

Explanation:

Metallic Bond: This is the bond that exists among the atoms of the metal. This is a type of electrostatic attraction between conduction electrons of metallic atom and their positively charged metal ions.

(figure attached)

Example:

Copper is a metallic element and its atoms consist of metallic bond among their selves.

Options A, B, D are not correct as all states for a kind of ionic bond formation.

Ionic bond:

It form by the complete transfer of electron from one atom to other

It is formed among two atoms of different electronegativities.

Also metals are electro-positive and non -metals are electro-negative so they form ionic bond.

Example is NaCl where sodium is a metal and Chloride is non-metal and they from ionic bond.

7 0

3 years ago

A sample of NaNo3 weighing 0.38g is placed in 50.0mL volumetric flask.The flask is then filled with water to the mark on the nec

snow_tiger [21]

Answer:

0.0894 M

Explanation:

So you first want to change the grams into moles (since molarity is moles solute per Liter solution).

The molar mass of NaNO3 is 84.995 g/mol, so we divide 0.38g of NaNO3 by 84.995 g/mol to get approximately 0.004471 mol NaNO3.

Now, all you have to do is to divide by the total Liters of water (your solution).

Since the volume is expressed in mL, you just need to divide by 1000 (1 L = 1000mL) to get 0.050 L solution.

Therefore, to get molarity, you divide 0.004471 mol by 0.050 L to get your answer of 0.0894 M.

5 0

3 years ago

What terms are needed to completely describe velocity...

Tpy6a [65]

A, b, and d. mass could be important in your calculations though.

5 0

3 years ago

A single amino acid change in Ras eliminates its ability to hydrolyze GTP, even in the presence of a GTPase-activating protein (

erica [24]

Answer:

Yes, this molecule will be useful in the treatment of cancer.

Explanation:

Generally ligand binds to RTK——————— > RTK dimer formation————— > autophosphorylation occurs in RTK—————— > RTK activation—————— > This RTK activates RAS—————- > which activates many cellular processes————- > cancer.

Already, it nanoparticle stops RTK dimerization. As a result, RTK will not be triggered but the above-described sequence of activities would not be able to happen (from bold above); therefore, cancer can be precluded.

8 0

4 years ago