Melting is a physical change in matter, so it doesn’t change the chemical makeup or chemical properties of matter.

1. Calculate the [H] in a solution that has a pH of 9.88.

Olenka [21]

The answer to the question is D.

5 0

2 years ago

Lactose, C12H22O11, is a naturally occurring sugar found in mammalian milk. A 0.335 M solution of lactose in water has a density

Dmitry_Shevchenko [17]

The molality of the solution is 0.00037 m.

<h3>What is concentration?</h3>

The term concentration refers to the amount of solute in a solution.

We have the following information;

Molarity = 0.335 M

Density = 1.0432 g/mL

Temperature = 20 o C

The molality of the solution is obtained from;

m = 0.335 M × 1.0432 g/mL/ 1000(1.0432 g/mL) - 0.335 M (342 g/mol)

m = 0.344/1043.2 - 114.57

m = 0.344/928.63

m = 0.00037 m

Learn more about molality of solution: brainly.com/question/4580605

5 0

2 years ago

How many formula units are there in 50.3 moles potassium chloride?

Alona [7]

<h3>Answer:</h3>

3.03 × 10²⁵ formula units KCl

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

<u>Chemistry</u>

Reading a Periodic Table
Writing Compounds

<u>Atomic Structure</u>

Using Dimensional Analysis
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<h3>Explanation:</h3>

<u>Step 1: Define</u>

50.3 mol KCl (Potassium chloride)

<u>Step 2: Identify Conversions</u>

Avogadro's Number

<u>Step 3: Convert</u>

<u /> $\displaystyle 50.3 \ mol \ KCl(\frac{6.022 \cdot 10^{23} \ formula \ units \ KCl}{1 \ mol \ KCl} )$ = 3.02907 × 10²⁵ formula units KCl

<u>Step 4: Check</u>

<em>We are given 3 sig figs. Follow sig fig rules and round.</em>

3.02907 × 10²⁵ formula units KCl ≈ 3.03 × 10²⁵ formula units KCl

6 0

3 years ago

Ammonium perchlorate nh4clo4 is a powerful solid rocket fuel, used in the space shuttle boosters. it decomposes into nitrogen n2

babymother [125]

2NH4ClO4 --------> N2 + Cl2 + 2O2 + 4H2O
from reaction 2 mol 1 mol
given x mol 0.10 mol

Proportion:
<u>2 mol NH4ClO4 </u>= <u>1 mol Cl2</u>
x mol NH4ClO4 0.10 mol Cl2

x= (2*0.10)/1 = 0.20 mol NH4ClO4

4 0

3 years ago

A sample of nitrogen gas is collected over water at temperature of 20.0˚C. What is the pressure of the nitrogen gas if atmospher

Levart [38]

Answer:

$P_N=0.987atm$

Explanation:

Hello there!

In this case, for these problems about collecting a gas over water, we must keep in mind that once the gas has been collected, the total pressure of the system is given by the atmospheric pressure, in this case 1.01 atm. Next, since we also have water in the mixture, we can write the following equation:

$P_T=P_w+P_N$

Thus, by solving for the pressure of nitrogen and using consistent units, we obtain:

$1.01atm=17.5torr*\frac{1atm}{760torr} +P_N\\\\P_N=1.01atm-0.023atm\\\\P_N=0.987atm$

4 0

2 years ago