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3 years ago

What number should be substituted for the question mark to balance the equation and why is that the correct number?

2 answers:

6 0

The combustion of ethane results in the balanced equation 2C2H6 + 7O2 -> 4CO2 + H2O + energy because we see that after the combustion, the reactants have 8 + 6 = 14 Oxygen atoms in total (8 from 4CO2, 6 from 6H2O). Therefore, since there are 2 atoms of Oxygen in oxygen gas, we have 7O2 molecules in the beginning to hold the ratio true.

sergeinik [125]3 years ago

6 0

To balance an equation, we need to make sure the amount of atoms on the reactants and the products.

How much oxygen's are on the reactants side?

Lets count, 4*2 = 8 and 6, so 8+6 = 14

Now, start to predict the number.

14/2 = 7

Answer: 7 is the correct answer

You might be interested in

A wire 3.22 m long and 7.32 mm in diameter has a resistance of 11.9 mΩ. A potential difference of 33.7 V is applied between the

Scorpion4ik [409]

Answer:

(a) Current is 2831.93 A

(b) $8.40A/m^2$

Explanation:

Length of wire l = 3.22 m

Diameter of wire d = 7.32 mm = 0.00732 m

Cross sectional area of wire

$A=\pi r^2=3.14\times 0.00366^2=4.20\times 10^{-5}m^2$

Resistance $R=11.9mohm=11.9\times 10^{-3}ohm$

Potential difference V = 33.7 volt

(A) current is equal to

$i=\frac{V}{R}=\frac{33.7}{11.9\times 10^{-3}}=2831.93A$

(B) Current density is equal to

$J=\frac{i}{A}$

$J=\frac{2831.93}{4.20\times 10^{-5}}=8.40A/m^2$

$R=\frac{\rho l}{A}$

$11.9\times 10^{-3}=\frac{\rho \times 3.22}{4.20\times 10^{-5}}$

$\rho =15.52\times 10^{-9}ohm-m$

4 0

2 years ago

While Sophia was driving to work, she tried to avoid hitting an animal and instead hit a parked car. As the car stopped, her bod

Andreyy89

This would be an illustration of Newton's first law of motion. Law of inertia, an object moving at constant velocity will keep moving at constant velocity until a force is acted upon it. Inertia is the tendency of an object to keep moving in a particular direction resisting to change, unless a force acts upon the object.

7 0

3 years ago

The atoms in a solid move about freely

ivolga24 [154]

No, not exactly. They jiggle and tremble and vibrate a lot, but
they always basically stay in very nearly the same place.

It's like if you're allowed to go anywhere you want in your jail cell,
you wouldn't exactly call that "moving about freely".

6 0

3 years ago

A .100 kg bullet is flying at 200 m/s. How much energy is the bullet storing due to its motion?

morpeh [17]

KE = 2000 J

Explanation:

KE = (1/2)mv^2

= (1/2)(0.100 kg)(200 m/s)^2

= 2000 J

4 0

2 years ago

A caterpillar climbs up a one-meter a wall. For every 2 cm it climbs up, it slides down 1 cm. It takes 10 minutes for the

valkas [14]

Answer:

1.5 m is ur answer

Explanation:

3 0

2 years ago