Which of these elements has a smaller atomic#? chlorine, cadmium, neon

When the equation below is balanced with the smallest possible integer coefficients, what is the coefficient for PH3?

Vikki [24]

Answer:

The coefficient for PH3 is 8. Option D is correct.

Explanation:

Step 1: The unbalanced equation

P2H4(g) ⇆ PH3(g) + P4(s)

Step 2: Balancing the equation

P2H4(g) ⇆ PH3(g) + P4(s)

On the left side we have 4x H (in P2H4), on the right side we have 3x H (in PH3). To balance the amount of H on both sides, we have to multiply P2H4 on the left side by 3 and PH3 on the right by 4.

3P2H4(g ) ⇆ 4PH3(g) + P4(s)

On the left side we have 6x P (in 3P2H4) on the right side we have 8x P (4x in 4PH3 and 4x in P4). To balance the amount of P on bot hsides, we have to multiply 3P2H4 by 2 and 4PH3 also by 2. Now the equation is balanced

6P2H4(g ) ⇆ 8PH3(g) + P4(s)

The coefficient for PH3 is 8. Option D is correct.

5 0

4 years ago

Air thermals are updrafts of warm air that rise from

Anastaziya [24]

Answer:

B. convection because warm air rises and cool air sinks.

Explanation:

The processes that enables birds to fly to higher altitudes without flapping their winds while riding air thermals is called convection.

Convection is one of the forms of heat transfer usually found in gases and liquids.

In convection density differences due to temperature changes causes the circulation.
Warm air is less dense and it is hotter.
It rises up from the surface where it is warmed
Cold air sinks to replace the warm air. Cold air form when the air loses its energy to the surrounding.
By virtue of this, birds are able to take advantage of it for their flight.

7 0

3 years ago

Uranium-238 had a half life of 4.5 billion years. A 100 g sample of U-238 has decayed until only 25 g remain. How long did it ta

Natasha2012 [34]

awnseris chemical hhhh Explanation:

6 0

3 years ago

At room temperature, table salt is a solid and mercury is a liquid. What conclusion can you draw about the melting points of the

Radda [10]

That salt has a higher melting point than mercury.

7 0

3 years ago

Read 2 more answers

You have 750 grams of water at 80° Celsius. Which of the following would lower the temperature of the water by 10° Celsius? (1 p

dem82 [27]

Answer:

adding 750 grams of water at 60° Celsius .

Explanation:

We can calculate the amount of heat lost from 750 grams of water at 80°C to be lowered by 10°C using the relation:

Q = m.c.ΔT,

Where, Q is the amount of heat lost by water (Q = ??? J).

m is the mass of water (m = 750.0 g).

c is the specific heat capacity of the water (c = 4.18 J/g.°C).

ΔT is the temperature difference (ΔT = final T - initial T = - 10.0°C, the temperature of water is lowered by 10.0°C).

∴ Q = m.c.ΔT = (750.0 g)(4.18 J/g.°C)(- 10.0°C) = - 31350.0 J = -31.350 kJ.

Now, we can calculate the Q that is gained by the different added amounts of water:

adding 750 grams of water at 50° Celsius :

ΔT = 70.0°C - 50.0°C = 20.0°C,

∴ Q = m.c.ΔT = (750.0 g)(4.18 J/g.°C)(20.0°C) = 62700.0 J = 62.70 kJ.

adding 325 grams of water at 60° Celsius :

ΔT = 70.0°C - 60.0°C = 10.0°C,

∴ Q = m.c.ΔT = (325.0 g)(4.18 J/g.°C)(10.0°C) = 13585.0 J = 13.585 kJ.

adding 750 grams of water at 60° Celsius :

ΔT = 70.0°C - 60.0°C = 10.0°C,

∴ Q = m.c.ΔT = (750.0 g)(4.18 J/g.°C)(10.0°C) = 31350.0 J = 31.350 kJ.

adding 1000 grams of water at 55° Celsius:

ΔT = 70.0°C - 55.0°C = 15.0°C,

∴ Q = m.c.ΔT = (1000.0 g)(4.18 J/g.°C)(15.0°C) = 62700.0 J = 62.70 kJ.

So, the right choice is:

adding 750 grams of water at 60° Celsius

8 0

4 years ago