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3 years ago

Find A, B, and C

1 answer:

8 0

Electrons = protons
protons = atomic number
protons + neutrons = atomic mass

Therefore: a) protons + 7 = 15
protons= 15 -7
protons= 8

B) Remember proton = atomic number
so atomic number = 8

C)Now we know the atomic number so we can easily check on the periodic table what element has an atomic number of 8, which is Oxygen

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What type of solid has the highest melting point?

dem82 [27]

Answer: B -Network solids

Ionic solids are held by positive and negative charged ions bonded by electrostatic forces. The electrostatic force is much stronger than dipole–dipole interactions, London dispersion forces, hydrogen bonding.

Molecular solids are held by dipole–dipole interactions, London dispersion forces, or hydrogen bonds. Benzene is an example of this. These inter-molecular force are much weaker than electrostatic force.

The metallic bonds are much weaker than electrostatic force. Similarly, in non-metallic solids the atoms are held by covalent bonds. These covalent bonds are weaker than the electrostatic force.

Thus we can conclude that electrostatic force is the strongest when compared to dipole–dipole interactions, London dispersion forces, hydrogen bonding,covalent and metallic bonds. Thus ionic solids will have the highest melting point as more energy is required to break the ionic bonds as this is the strongest bond compared to the other bonds.

8 0

3 years ago

Read 2 more answers

How is a series circuit different from a parallel circuit?

beks73 [17]

Answer:

C. A series circuit has only one loop and a parallel circuit has two or more loops for the current to flow through

Explanation:

A circuit that are made of one loop is called series circuit. On the other hand, the parallel circuit has at least two loops. The circuit type has nothing to do with open or closed circuit.

If any part of the series circuit got cut, the current will stop flowing since there is only one loop. A parallel circuit has more loop so the circuit might still work even if a part of the circuit got cut.

4 0

3 years ago

There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. In

adell [148]

Answer:

The net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide is 523.2 kJ.

Explanation:

Step 1:

$CaC_2(s) + 2H_2O(g)\rightarrow C_2H_2(g) + Ca(OH)_2(s),\Delta H_1=414.0 kJ$ ...[1]

Step 2 :

$6C_2H_2(g) + 3CO_2(g) + 4H_2O(g)\rightarrow 5CH_2CHCO_2H(g) \Delta H_2=132.0kJ$ ..[2]

Adding 6 × [1] and [2]:

$6CaC_2(s) + 12H_2O(g)\rightarrow 6C_2H_2(g) + 6Ca(OH)_2(s)$

$6C_2H_2(g)+3CO_2(g)+16H_2O(g)\rightarrow 5CH_2CHCO_2H(g)$

we get :

$6CaC_2(s) + 8H_2O(g)+3CO_2(g)\rightarrow 5CH_2CHCO_2H(g)+ 6Ca(OH)_2(s),\Delta H'=?$

$\Delta H'=6\times \Delta H_1+\Delta H_2$

$\Delta H'=6\times 414.0 kJ+132.0kJ$

$\Delta H'=2,626 kJ$

Energy released on formation of 5 moles of acrylic acid = 2,626 kJ

Energy released on formation of 1 mole of acrylic acid:

$\frac{ 2,626 kJ}{5 } = 523.2 kJ$

7 0

4 years ago

The bonds in the reactants of Figure 7-3 contained 372 kJ of chemical energy and the bonds in the products contained 350 kJ of c

satela [25.4K]

Answer: 22 kJ amount of energy is released in the following reaction.

Explanation: There are two types of reaction on the basis of amount of heat absorbed or released.

1. Endothermic reactions: These are the type of reactions in which reactants absorb heat to form the products. The energy of the reactants is less than the energy of the products.

2. Exothermic reactions: These are the type of reactions in which heat is released from the chemical reactions. The energy of the products is less than the reactants.

Sign convention for $\Delta H$ : This value is negative for exothermic reactions and positive for endothermic reactions.

For the given chemical reaction,

Energy of the products is less than the energy of the reactants, Hence, this reaction will be a type of exothermic reaction and energy will be released during this chemical change.

Amount of energy released = (350 - 372) kJ = -22kJ

Negative sign symbolizes the energy is being released. So, 22 kJ amount of energy is released in the following reaction.

6 0

3 years ago

Titration of a 20.0-mL sample of acid rain required 1.7 mL of 0.0811 M NaOH to reach the end point. If we assume that the acidit

Rasek [7]

Answer:

Concentration of sulfuric acid in the acid rain sample is 0.0034467 mol/L.

Explanation:

Volume of NaOH = 1.7 ml = 0.0017 L

Molarity of NaOH = 0.0811 M

Moles of NaOH = n