Ask question

Ask question

All categories

3 years ago

15

Which example provides a complete scientific description of an object in motion? Question 3 options: The marble changed position

quickly. The car traveled north. The marble moved 30 cm north in 6 seconds. The ball rolled 20 cm in 5 seconds.

2 answers:

OlgaM077 [116]3 years ago

7 0

Answer:

The marble moved 30 cm north in 6 seconds. is correct

Explanation:

according to K12

100% sure

Contact [7]3 years ago

3 0

The answer is the Car Traveling North... According to me

You might be interested in

HURRY! 10 POINTS!!

frosja888 [35]

Answer:

Weak bonds require less energy to form than strong bonds

Explanation:

According to Coulomb's law, the force between two species is inversely proportional to the distance between them. That said, the bigger the atoms are, the greater the bond length should be to form a molecule.

As a result, for a greater bond length, the attraction force is lower than for a shorter bond length. This implies that large atoms would form weak bonds and small atoms would form strong bonds.

Bond energy is defined as the amount of energy required to break the bond. If a bond is weak, it would require a low amount of energy to break it. This is also true for energy of formation, as it's the same process taking place in the opposite direction.

6 0

3 years ago

Electromagnetic waves do not need to carry blank. Electromagnetic waves carry enough through matter, but they also carry enough

Setler [38]

Answer: what? whats the quiestion?

Explanation:

6 0

3 years ago

In their notebook you see that it takes 9 hours for a sixth of a 0.5M solution of BC2 to react. Unfortunately, you have somewher

trasher [3.6K]

Complete Question

The complete question is shown on the first uploaded image

Answer:

The concentration of $BC_2$ that should used originally is $C_Z_o = 0.4492M$

Explanation:

From the question we are told that

The necessary elementary step is

$2BC_2 ----->4C + B_2$

The time taken for sixth of 0.5 M of reactant to react $t = 9 hr$

The time available is $t_a = 3.5 hr$

The desired concentration to remain $C = 0.42M$

Let Z be the reactant , Y be the first product and X the second product

Generally the elementary rate law is mathematically as

$-r_Z = kC_Z^2 = - \frac{d C_Z}{dt}$

Where k is the rate constant , $C_Z$ is the concentration of Z

From the elementary rate law we see that the reaction is second order (This because the concentration of the reactant is raised to power 2 )

For second order reaction

$\frac{1}{C_Z} - \frac{1}{C_Z_o} = kt$

Where $C_Z_o$ is the initial concentration of Z which a value of $C_Z_o = 0.5M$

From the question we are told that it take 9 hours for the concentration of the reactant to become

$C_Z = C_Z_o - \frac{1}{6} C_Z_o$

$C_Z = 0.5 - \frac{0.5}{6}$

$= 0.4167 M$

So

$\frac{1}{0.4167} - \frac{1}{0.50} = 9 k$

$0.400 = 9 k$

=> $k = 0.044\ L/ mol \cdot hr^{-1}$

For $C_Z = 0.42M$

$\frac{1}{0.42} - \frac{1}{C_Z_o} = 3.5 * 0.044$

$2.38 - 0.154 = \frac{1}{C_Z_o}$

$2.226 = \frac{1}{C_Z_o}$

$C_Z_o = \frac{1}{2.226}$

$C_Z_o = 0.4492M$

4 0

3 years ago

A chemist adds 215.0mL of a 6.0x10^−5/mmolL mercury(II) iodide HgI2 solution to a reaction flask. Calculate the micromoles of me

Snezhnost [94]

The micromoles of mercury(II) iodide : 0.013 μ moles

<h3>Further explanation</h3>

Given

215.0mL of a 6.0x10⁻⁵mmol/L HgI₂

Required

micromoles of HgI₂

Solution

Molarity(M) = moles of solute per liters of solution

Can be formulated :

M = n : V

n = moles

V = volume of solution

V = 215 mL = 0.215 L

so moles of solution :

n = M x V

n = 6.10 mmol/L x 0.215 L

n = 1.312 . 10⁻⁵ mmol

mmol = 10³ micromol

so 1.312 mmol = 1.312.10⁻⁵ x 10³ = 0.01312 micromoles ⇒ 2 sif fig = 0.013 μ moles

6 0

2 years ago

PLEASE HELP, 5 STARS, 35 POINTS + PRIZE The reaction C4H8(g)⟶2C2H4(g) has an activation energy of 262 kJ/mol. At 600.0 K, the ra

Ghella [55]

Answer:

346 hope this is helpfull

5 0

3 years ago