Perform the following

MaRussiya [10]

Answer:

You need to count all the atoms on each side of the chemical equation. once you know how many of each type of atom you have,you can only change the coefficient. (the numbers in front of the atoms or compounds

7 0

2 years ago

A chemist prepares a solution of sodium carbonate by measuring out of sodium carbonate into a volumetric flask and filling the f

Vadim26 [7]

Answer:

The correct answer will be " $9.45\times 10^{-5} \ mol/L$ ".

Explanation:

We have:

Moles of solute (Na₂Co₃) = $18.9 \mu \ mol$

= $18.9\times 10^{-6}$

$1 \mu \ mol$ = $10^{-6} \ mol$

Now,

The volume of the solution will be:

⇒ $0.200 \ L$

∴ ${1 \ mL=0.001 \ L}$

The formula to find the concentration will be:

⇒ $Concentration = \frac{moles \ of \ solute \ (mol)}{Volume \ of \ solution \ (L)}$

On substituting the given values, we get

⇒ $=\frac{18.9\times 10^{-6}}{0.200}$

⇒ $=9.45\times 10^{-5} \ mol/L$

8 0

3 years ago

Where are the most reactive metals located?

Lapatulllka [165]

Answer:

option B = lower left of the periodic table

Explanation:

The most reactive metals are located at the bottom left corner of periodic table. These metals are reactive in the sense that they can react with water very easily.

Examples include lithium, sodium potassium. As we move down the group in this column metallic character increase. Their atomic radius also increases and electron can easily donated. which means metals became more reactive.

These metals can also react very easily with O2 in atmosphere that's way these are stored in inert atmosphere. The most reactive metal in periodic table is francium.

7 0

3 years ago

Read 2 more answers

How many moles are in 2.8x10^24 atoms of silicon?

sergejj [24]

Answer:

4.6 mol Si

General Formulas and Concepts:

Atomic Structure

Reading a Periodic Table
Moles
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Stoichiometry

Using Dimensional Analysis

Explanation:

Step 1: Define

[Given] 2.8 × 10²⁴ atoms Si

[Solve] moles Si

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

[DA] Set up: $\displaystyle 2.8 \cdot 10^{24} \ atoms \ Si(\frac{1 \ mol \ Si}{6.022 \cdot 10^{23} \ atoms \ Si})$
[DA] Divide [Cancel like units]: $\displaystyle 4.64962 \ mol \ Si$

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

4.64962 mol Si ≈ 4.6 mol Si

6 0

2 years ago

Which of the following pairs of elements will form covalent bonds with each other? PLEASE HELP

Oksana_A [137]

<h3>Answer: Your correct answer is A, because potassuim and bromine form covalent bonds with each other, Also check out nile red he made bromine in his dads garage!-Have a nice day :)</h3>

8 0

2 years ago