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
emmasim [6.3K]
3 years ago
5

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

Physics
2 answers:
grigory [225]3 years ago
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 120-V rms voltage at 60.0 Hz is applied across an inductor, a capacitor, and a resistor in series. If the rms value of the cur
klemol [59]

Answer:

The impedance of this circuit is 200 ohm.

Explanation:

Given that,

rms voltage = 120 v

Frequency = 60.0 Hz

rms current = 0.600 A

We need to calculate the impedance

Using formula of impedance

Z=\dfrac{V_{rms}}{I_{rms}}

Where, V_{rms} = rms voltage

I_{rms} = rms current

Z= impedance

Put the value into the formula

Z=\dfrac{120}{0.600}

Z=200\ Omega

Hence, The impedance of this circuit is 200 ohm.

8 0
3 years ago
A tug-of-war game is played by five c/hildren: three on one team and two on the other. How much force will the two child team ha
dem82 [27]

Answer:

no, 3 porces is more tha 2 so the power between the 3 should be more than 2

Explanation:

4 0
3 years ago
A fish inside the water 12cm below the surface looking up through the water sees the outside world contained in a circular horiz
serg [7]

Answer:

13.6 cm

Explanation:

From Snell's law:

n₁ sin θ₁ = n₂ sin θ₂

In the air, n₁ = 1, and light from the horizon forms a 90° angle with the vertical, so sin θ₁ = sin 90° = 1.

Given n₂ = 4/3:

1 = 4/3 sin θ

sin θ = 3/4

If x is the radius of the circle, then sin θ is:

sin θ = x / √(x² + 12²)

sin θ = x / √(x² + 144)

Substituting:

3/4 = x / √(x² + 144)

9/16 = x² / (x² + 144)

9/16 x² + 81 = x²

81 = 7/16 x²

x ≈ 13.6

4 0
3 years ago
How much work is done when a porcelain vase with mass of 2.5 kg is lifted up 3 m to a shelf? (HINT- Weight can be used as Force
alexdok [17]
Work = force x distance
F= 2.5
D= 3
Work = 2.5 x 3 =7.5
Work = 7.5 J
J=Jules (Jules is the unit uses to calculate work)
8 0
3 years ago
A 6.2 kg object moving in the +x direction at 5.3 m/s collides head-on with an 7.8 kg object moving in the −x direction at 2.5 m
Crank

Answer:

10ms kg 88.2

Explanation:

Toook test

8 0
3 years ago
Other questions:
  • Listed following are three possible models for the long-term expansion (and possible contraction) of the universe in the absence
    13·1 answer
  • An end of a light wire rod is bent into a hoop of radius r. The straight part of the rod has length l; a ball of mass M is attac
    10·1 answer
  • What happens to the amplitude of the resultant wave when two sound waves with equal amplitude constructively interfere?
    5·2 answers
  • What makes silver and gold different by using the terms atom and element
    8·1 answer
  • A woman stands on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale briefly reads only 0.90
    10·1 answer
  • The potential energy of an object attached to a spring is 2.60 J at a location where the kinetic energy is 1.40 J. If the amplit
    13·1 answer
  • A gas has a volume of 8.21 mL and exerts a pressure of 2.9 atm. What new volume will the gas have if the pressure is changed to
    10·1 answer
  • If the mass of a ball B is 1 kilogram and it’s speed is 1 m/sec. the mass and the speed of ball A is three times the mass and sp
    11·2 answers
  • On a certain map, every 3 cm represents 6 km on earth surface. Which ratio represents the scale of the map, which shows how the
    12·1 answer
  • An object of mass m moves horizontally, increasing in speed from 0 to v in a time t. The power necessary to accelerate the objec
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!