All categories

3 years ago

Please help!! I don’t understand

Chemistry

1 answer:

laiz [17]3 years ago

4 0

<h3>Answer:</h3>

150 g Si

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

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

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

<u>Stoichiometry</u>

Use Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[Given] 3.2 × 10²⁴ atoms Si

[Solve] grams Si

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

Avogadro's Number

[PT] Molar Mass of Si - 28.09 g/mol

<u>Step 3: Convert</u>

[DA] Set up: $\displaystyle 3.2 \cdot 10^{24} \ atoms \ Si(\frac{1 \ mol \ Si}{6.022 \cdot 10^{23} \ atoms \ Si})(\frac{28.09 \ g \ Si}{1 \ mol \ Si})$
[DA] Multiply/Divide [Cancel out units]: $\displaystyle 149.266 \ g \ Si$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. Instructed to round to 2 sig figs.</em>

149.266 g Si ≈ 150 g Si

You might be interested in

A chemist studies the reaction below. 2NO(g) + Cl2(g) 2NOCl(g) He performs three experiments using different concentrations and

Dmitry_Shevchenko [17]

Answer:

1. $Rate =k [NO]^{2}[Cl_{2}]$

2. $k= 0.42 \frac{L^{2}}{mol^{2}*s}$

Explanation:

$Rate =k [NO]^{m}[Cl_{2}]^{n}$

$Rate1 = k[0.4]^{m}[0.3]^{n}=0.02\\Rate 2=k [0.8]^{m}[0.3}]^{n}=0.08\\\\\frac{Rate1}{Rate2}=\frac{0.02}{0.08} =\frac{k[0.4]^{m}[0.3]^{n}}{k[0.8]^{m}[0.3]^n}} \\\\\frac{1}{4} =(\frac{1}{2} )^{m},\\m=2$

$Rate3 =k [0.8]^{m}[0.6]^{n}=0.16\\Rate 2= k[0.8]^{m}[0.3}]^{n}=0.08\\\\\frac{Rate3}{Rate2}=\frac{0.16}{0.08} =\frac{k[0.8]^{m}[0.6]^{n}}{k[0.8]^{m}[0.3]^n}} \\\\\frac{2}{1} =(\frac{2}{1} )^{n},\\n=1$

$Rate =k [NO]^{2}[Cl_{2}]^{1}$

$Rate =k [NO]^{2}[Cl_{2}]^{1}\\Rate 1=k [0.4]^{2}[0.3]^{1} =0.02\\k*0.16*0.3=0.02\\k=\frac{0.02}{0.16*0.3}=\frac{1}{8*(\frac{3}{10} )}=\frac{5}{12} = 0.42 \frac{L^{2}}{mol^{2}*s}$

6 0

3 years ago

Write a hypothesis to predict how reaction rate will change when temperature changes. For example: “ If i heat a reaction, then

cricket20 [7]

If I heat a reaction then the rate will increase because the higher the temperature the faster the reaction.

Please vote my answer brainliest. thanks!

8 0

3 years ago

A 50.0 mL graduated cylinder has a mass of 65.1 g. When it is filled with an unknown liquid to the 49.3 mL mark, the cylinder an

Delvig [45]

<u>Answer:</u> The density of liquid is $1.12g/cm^3$

<u>Explanation:</u>

We are given:

Mass of cylinder, $m_1$ = 65.1 g

Mass of liquid and cylinder combined, M = 120.5 g

Mass of liquid, $m_2$ = $(M-m_1)=(120.5-65.1)g=55.4g$

To calculate density of a substance, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

We are given:

Mass of liquid = 55.4 g

Volume of liquid = 49.3 mL = $49.3 cm^3$ (Conversion factor: $1mL=1cm^3$ )

Putting values in above equation, we get:

$\text{Density of liquid}=\frac{55.4g}{49.3cm^3}\\\\\text{Density of liquid}=1.12g/cm^3$

Hence, the density of liquid is $1.12g/cm^3$

3 0

3 years ago

Wharis the mass in grams of 2.000 mol of oxygen atoms?

Alika [10]

Answer:

32.00 g. Hope this helps! PLEASE GIVE ME BRAINLIEST!!!!! =)

8 0

3 years ago

Changes in the composition of the atmosphere have caused gradual changes in earth's _______ throughout history, causing changes

bearhunter [10]

climate

Changes in the composition of the atmosphere have caused gradual changes in earth's <u>climate</u> throughout history, causing changes in plant and animal life that contributed to mass extinctions.

The following are some of the reasons:

UV light
climate
pollutants
hydrofluorocarbons

heat

The surface of the Earth warms up as sunlight strikes it.
Surface-emitted infrared light is absorbed in the atmosphere and transformed into heat.
The temperature close to the surface rises as a result of this heat being trapped in the atmosphere.

<h3>UV light:</h3>

indirect impacts of climate change on UV radiation from the surface.
By changing the concentrations of ozone, UV-absorbing tropospheric gases, aerosols, and clouds in the atmosphere, climate change may have indirectly affected UV radiation levels in the past.
These influences are probably going to persist in the future.

<h3>climate:</h3>

People are at risk from food and water shortages, greater flooding, high heat, an increase in disease, and economic loss due to climate change.
Conflict and human migration are potential outcomes.
Climate change is the top hazard to world health in the twenty-first century, according to the World Health Organization (WHO).

<h3>pollutants:</h3>

these are also resulting in the increase of temperature of the Earth and is also damaging ozone layer.

To learn more about the changes in earth visit:

brainly.com/question/13434833?

#SPJ4

6 0

1 year ago