The elements in the periodic table are arranged in order of

2Fe + 6HCl -> 2FeCl3 + 3H2 If 7.0 moles of HCl is added to enough iron that the HCl is completely used up, how many

DENIUS [597]

Answer: 3.5 moles of hydrogen gas will be produced.

Explanation:

The balanced chemical equation is:

$2Fe+6HCl\rightarrow 2FeCl_3+3H_2$

As HCl gets completely used up, $HCl$ is the limiting reagent.

According to stoichiometry :

6 moles of $HCl$ produces = 3 moles of $H_2$

Thus 7.0 moles of $HCl$ produces= $\frac{3}{6}\times 7.0=3.5moles$ of $H_2$

Thus 3.5 moles of hydrogen gas will be produced.

3 0

2 years ago

Find the density of a piece of chocolate with these measurements: 2.4 g and 5.12 mL

Dahasolnce [82]

Answer:

0.46875g/ml

Explanation:

Density(p) = m / v unit - g/ml or Kg/m^3

Given

mass = 2.4g

volume = 5.12ml

p = m / v

= 2.4g / 5.12ml

= 0.46875g/ml

5 0

2 years ago

when 10.00 g of phosphorus reacts with oxygen, it produces 17.77 g of a phosphorus oxide. This phosphorus oxide was found to hav

Alex_Xolod [135]

Answer:

Molecular formula = P₄O₆

Explanation:

P(s) + O₂(g)------------------------------------⇒ PₓOₙ (g)

10g (17.77-10)g 17.77g

10g 7.77g 17.77g (gramme ratio)

The molecular mass of Phosphorus (P) = 31g/mole

The molecular mass of Oxygen atom (O) = 16g/mole

Mole ratio is given by:

P : O

10/31 7.77/16

0.3226 : 0.4856 Mole ratio---------------------------- (1)

Divide (1) through by 0.3226

1 : 1.5-------------------------------------------- (2)

From (2), the empirical formula for Phosphorus oxide :

Empirical formula = P₁O₁.₅

= PO₁.₅

The molecular formula can be calculated from below:

Since the molecular formula is a multiple of the empirical formula we have

Molecular formula = (PO₁.₅)ₙ----------------------------------- (3)

Since we are given the molecular mass of the oxide formed, we have:

(PO₁.₅)ₙ = 220-----------------------------(4)

[31 + (16 x 1.5)] x n = 220

[31 + 24]n = 220

55n =220

n = 4

Substituting into (3), we have :

Molecular formula = (PO₁.₅)₄

= P₄O₆

8 0

3 years ago

The temperature of a 500. ml sample of gas increases from 150. k to 350. k. what is the final volume of the sample of gas, if th

maw [93]

<span>pv=nrt; Pressure and moles are constant. p=nr(150k)/.5 L; Pressure initially After temp change pv=nrt; What is volume? v=nr(350k)/p; p is constant so we can substitute from above v=nr(350k)/(nr(150k)/.5 L)) v=350/150/.5 L v=4.66 liters</span>

3 0

3 years ago

Read 2 more answers

A doorknob makes it easier for you to open doors because it is what type of simple machine?

vagabundo [1.1K]

Answer: Wheel and Axle

Both of these work together to form a simple machine. You can't have one without the other.

If you try to turn just the axle itself, then you'll find it takes a lot of work. This is because the inertia of the axle wants to keep the object at rest. Also, you won't have a lot of torque due to the small radius compared to what a doorknob can offer.

Using a doorknob is like putting a (steering) wheel on an axle. This increases the radius and therefore increases the torque. You put in less work into the system and get more out of it.

5 0

2 years ago