All categories

3 years ago

What number should be placed in front of Fe to balance this chemical

Chemistry

1 answer:

andrew-mc [135]3 years ago

6 0

the answer is B. 2

because there is 2 iron on the right side so you need another two on the left side to balance it out

You might be interested in

The half-life of plutonium-239 is 24300. If a nuclear bomb released 8kg of this isotope, how many years would pass before the am

Aneli [31]

Answer:

= 72900 years

Explanation:

The half-life is the time taken by a radioactive material to decay by half the original amount.
The half-life of plutonium-239 is 24300 years which means it takes 24300 years to decay by half the original amount.

To calculate the time taken for a mass of 8 kg to decay to 1 kg we use;

New mass = Original mass x (1/2) ^n, where n is the number of half-lives

Therefore;

1 kg = 8 kg × (1/2)^n

1/8 = (1/2)^n

solving for n;

n =3

Therefore;

Time = 3 × 24300 years

= 72900 years

It will, therefore, take 72900 years for 8 kg of plutonium-239 to decay to 1 kg.

3 0

3 years ago

The name of CuO is --

Vesnalui [34]

The name is Copper(II) Oxide and/or Cupric Oxide.

Cu is Copper and O is Oxygen.

Usually when the Oxygen ion is placed after another, it's name is Oxide.

6 0

3 years ago

The flask contains 10.0 mL of HCl and a few drops of phenolphthalein indicator. The buret contains 0.160 M NaOH. It requires 18.

olchik [2.2K]

Answer:

Approximately $0.291\; \rm M$ (rounded to two significant figures.)

Explanation:

The unit of concentration $\rm M$ is the same as $\rm mol \cdot L^{-1}$ (moles per liter.) On the other hand, the volume of both the $\rm NaOH$ solution and the original $\rm HCl$ solution here are in milliliters. Convert these two volumes to liters:

$V(\mathrm{NaOH}) = 18.2\; \rm mL = 18.2 \times 10^{-3}\; \rm L = 0.0182\; \rm L$ .
$V(\text{$\mathrm{HCl}$, original}) = 10.0\; \rm mL = 10.0\times 10^{-3}\; \rm L = 0.0100\; \rm L$ .

Calculate the number of moles of $\rm NaOH$ in that $0.0182\; \rm L$ of $0.160\; \rm M$ solution:

$\begin{aligned} n(\mathrm{NaOH}) &= c(\mathrm{NaOH})\cdot V(\mathrm{NaOH})\\ &= 0.160\; \rm mol \cdot L^{-1} \times 0.0182\; \rm L \approx 0.00291\; \rm mol\end{aligned}$ .

$\rm HCl$ reacts with $\rm NaOH$ at a one-to-one ratio:

$\rm HCl\; (aq) + NaOH\; (aq) \to NaCl\; (aq) + H_2O\; (l)$ .

Coefficient ratio:

$\displaystyle \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} = 1$ .

In other words, one mole of $\rm NaOH$ would neutralize exactly one mole of $\rm HCl$ . In this titration, $0.291\; \rm mol$ of $\rm NaOH\!$ was required. Therefore, the same amount of $\rm HC$ should be present in the original solution:

$\begin{aligned}&n(\text{$\mathrm{HCl}$, original})\\ &= n(\mathrm{NaOH})\cdot \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} \\ &\approx 0.00291\; \rm mol \times 1 = 0.00291\; \rm mol\end{aligned}$ .

Calculate the concentration of the original $\rm HCl$ solution:

$\displaystyle c(\text{$\mathrm{HCl}$, original}) = \frac{n(\text{$\mathrm{HCl}$, original})}{V(\text{$\mathrm{HCl}$, original})} \approx \frac{0.00291\; \rm mol}{0.0100\; \rm L} \approx 0.291\; \rm M$ .

5 0

3 years ago

An ion is an atom that has has gained or lost:

Elena L [17]

Electrons, specifically valence electrons

5 0

3 years ago

There are seven types of crystals. Which of these is not one of the seven?

Gelneren [198K]

The answer is B. tetraclinic

3 0

3 years ago

Read 2 more answers