What is the density of a 4400. g/cm^3gram brick that is 5.00 inches x 3.00 inches x 2.00 inches?

a radio controlled airplane is moving at a velocity of 23 m/s. it accelerates to a velocity of 85 m/s in 9.3 seconds. what accel

tatuchka [14]

I will show you a method to find a velocity of anything:-

Find average velocity when acceleration is constant.

Set up an equation with position and time instead.

Find the distance between the start and end points.

Calculate the change in time.

Divide the total displacement by the total time.

Solve problems in two dimensions.

7 0

3 years ago

Which reactions are single displacement reactions? 2NaBr + CaF2 → 2NaF + CaBr2 SnO2 + 2H2 → Sn + 2H2O 4Na + O2 → 2Na2O 2KClO3 →

r-ruslan [8.4K]

Answer : The correct options are, $SnO_2+2H_2\rightarrow Sn+2H_2O$ and $2Al+6HCl\rightarrow 2AlCl_3+3H_2$

Explanation :

Single displacement reaction : It is a type of chemical reaction in which the more reactive element displaces the less reactive element.

Option A reaction : $2NaBr+CaF_2\rightarrow 2NaF+CaBr_2$

It is an example of double displacement reaction because in this reaction a positive cation and a negative anion of the two reactants exchange their places to form two new products.

Option B reaction : $SnO_2+2H_2\rightarrow Sn+2H_2O$

It is an example of single displacement reaction.

Option C reaction : $4Na+O_2\rightarrow 2Na_2O$

It is an example of combination reaction because in this reaction two reactants react to give a single product.

Option D reaction : $2KClO_3\rightarrow 2KCl+3O_2$

It is an example of decomposition reaction because in this reaction a single reactant decomposes into two or more products.

Option E reaction : $2Al+6HCl\rightarrow 2AlCl_3+3H_2$

It is an example of single displacement reaction because in this reaction the most react element, aluminium displaces the less reactive element, hydrogen.

Hence, the options B and E are single displacement reactions.

5 0

3 years ago

The organic compound di‑n‑butyl phthalate, C 16 H 22 O 4 ( l ) , C16H22O4(l), is sometimes used as a low‑density ( 1.046 g ⋅ mL

damaskus [11]

Answer:

36.63 Torr

Explanation:

You need to use two expressions, one for pressure and the other with the relation of density and height of the column.

For the pressure:

P = h * d * g (1)

h is height.

d density

g gravity

The second expression put a relation between the densities and height of the column so:

d1/d2 = h1/h2 (2)

let 1 be the phthalate, and 2 the mercury.

Let's calculate first the relation of density:

d1/d2 = 13.53 / 1.046 = 12.93

Now with the first expression, we can calculate the pressure so:

P = hdg

We have two compounds so,

h1d1g = h2d2g ---> gravity cancels out

From here, we can solve for h2:

h2 = h1*(d1/d2)

replacing:

h2 = 459 / 12.53

h2 = 36.63 mm

1 mmHg is 1 torr, therefore the pressure of the gas in Torr would be 36.63 Torr

8 0

3 years ago

How many moles are in 2.98x10^23 particles?

Novosadov [1.4K]

Answer:

$\boxed {\boxed {\sf 0.495 \ mol}}$

Explanation:

We are given a number of particles and asked to convert to moles.

<h3>1. Convert Particles to Moles </h3>

1 mole of any substance contains the same number of particles (atoms, molecules, formula units) : 6.022 *10²³ or Avogadro's Number. For this question, the particles are not specified.

So, we know that 1 mole of this substance contains 6.022 *10²³ particles. Let's set up a ratio.

$\frac { 1 \ mol }{6.022*10^{23 } \ particles}}$