How many significant figures in 368.1371 ?

3. Does the siren of a moving police car seem to change pitch to the

FinnZ [79.3K]

Answer:

As the police car moves towards them, the pitch of the police car's siren goes up because the sound waves get closer together in front of the police car. When the police car moves away from the person, the pitch goes down because the waves spread out behind the police and that makes the frequency go down.

Explanation:

4 0

3 years ago

QUESTION 21 The combustion of ammonia in the presence of excess oxygen yields NO 2 and H 2O: 4 NH 3 (g) 7 O 2 (g) 4 NO 2 (g) 6 H

Harrizon [31]

Answer:

The answer to your question is 47.44 g of Oxygen

Explanation:

Data

mass of Ammonia = 14.4 g

mass of Oxygen = ?

Balanced chemical reaction

4NH₃ + 7O₂ ⇒ 4NO₂ + 6H₂O

Process

1.- Calculate the molar mass of Ammonia

NH₃ = 4[(1 x 14) + (3 x 1)] = 4[14 + 3] = 4[17] = 68 g

2.- Calculate the molar mass of Oxygen

O₂ = 7[16 x 2] = 7[32] = 224 g

3.- Use proportions to calculate the mass of Oxygen

68g of NH₃ --------------------- 224 g of O₂

14.4 g of NH₃ ----------------- x

x = (14.4 x 224) / 68

x = 3225.6/ 68

x = 47.44 g

5 0

3 years ago

6) Mr. Collins finally decided to take this seriously and put both hands on the rope and applied a 500 N force to the left,

natali 33 [55]

Answer:

I'm pretty sure the net force is 200 N and the direction of motion is left

Explanation:

500 - 300 = 200 and more force is coming from and pulling toward the left.

5 0

3 years ago

When silver nitrate is added to an aqueous solution of magnesium chloride, a precipitation reaction occurs that produces silver

Aloiza [94]

Answer:

103.62 g of AgCl.

Explanation:

Step 1:

The balanced equation for the reaction. This is given below:

2AgNO3 + MgCl2 —> 2AgCl + Mg(NO3)2

Step 2:

Determination of the mass of MgCl2 that reacted and the mass of AgCl produced from the balanced equation.

This is illustrated below:

Molar mass of MgCl2 = 24 + (2x35.5) = 95 g/mol

Mass of MgCl2 from the balanced equation = 1 x 95 = 95 g

Molar mass of AgCl = 108 + 35.5 = 143.5 g/mol

Mass of AgCl from the balanced equation = 2 x 143.5 = 287 g

Thus, from the balanced equation above,

95 g of MgCl2 reacted to produce 287 g of AgCl.

Step 3:

Determination of the mass of AgCl produced from the reaction of 34.3 g of MgCl2.

The mass of AgCl produced from the reaction can be obtained as follow:

Form the balanced equation above,

95 g of MgCl2 reacted to produce 287 g of AgCl.

Therefore, 34.3 g of MgCl2 will react to produce = (34.3 x 287)/95 = 103.62 g of AgCl.

Therefore, 103.62 g of AgCl were produced from the reaction.

8 0

4 years ago

Given the reaction below:

lidiya [134]

The given equation is is

$2Cu+8HNO_{3}-->3Cu(NO_{3})_{2}+2NO+4H_{2}O$

this is not balanced

The balanced equation will be:

$3Cu+8HNO_{3}-->3Cu(NO_{3})_{2}+2NO+4H_{2}O$

Now as per it if we are using eight moles of HNO3 we are getting two moles of NO

so for each mole of NO we have to take four moles of HNO3

Hence the mole ratio of NO produced to HNO3 reacted will be = 1:4

4 0

3 years ago