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3 years ago

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A student has a sample of isopropanol (C3H7OH) that has a mass of 78.6 g. The molar mass of isopropanol is 60.1 g/mol. How many

moles of isopropanol are contained in this sample?

1 answer:

vivado [14]3 years ago

5 0

78.6 g (1mol/60.1 g)= 1.31 moles of isopropanol

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When water and alcohol are mixed, the final volume is less than the total of volume of alcohol plus water added due to .......

tigry1 [53]

Answer:

molecules take up more space

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2 years ago

Using the balanced equation below,

Zielflug [23.3K]

Answer:

Mass = 6.538 g

Explanation:

Given data:

Mass of zinc hydroxide produced = 9.65 g

Mass of zinc required = ?

Solution:

Chemical equation:

Zn + 2MnO₂ + H₂O → Zn(OH)₂ + Mn₂O₃

Number of moles of zinc hydroxide:

Number of moles = mass/molar mass

Number of moles = 9.65 g/ 99.42 g/mol

Number of moles = 0.1 mol

now we will compare the moles of zinc and zinc hydroxide,

Zn(OH)₂ : Zn

1 : 1

0.1 : 0.1

Mass of zinc required:

Mass = number of moles × molar mass

Mass = 0.1 mol × 65.38 g/mol

Mass = 6.538 g

8 0

2 years ago

Read 2 more answers

SOMEONE PLEASE HELP

Zinaida [17]

Answer:

6. 7870 kg/m³ (3 s.f.)

7. 33.4 g (3 s.f.)

8. 12600 kg/m³ (3 s.f.)

Explanation:

6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.

1 kg= 1000g

1m³= 1 ×10⁶ cm³

Mass of iron bar

= 64.2g

= 64.2 ÷1000 kg

= 0.0642 kg

Volume of iron bar

= 8.16 cm³

= 8.16 ÷ 10⁶

$= 8.16 \times 10^{ - 6} \: kg$

$\boxed{density = \frac{mass}{volume} }$

Density of iron bar

$= \frac{0.0642}{8.16 \times 10^{ - 6} }$

= 7870 kg/m³ (3 s.f.)

7.

$\boxed{mass = density \: \times volume}$

Mass

= 1.16 ×28.8

= 33.408 g

= 33.4 g (3 s.f.)

8. Volume of brick

= 12 cm³

$= 12 \times 10^{ - 6} \: m^{3} \\ = 1.2 \times 10^{ - 5} \: m ^{3}$

Mass of brick

= 151 g

= 151 ÷ 1000 kg

= 0.151 kg

Density of brick

= mass ÷ volume

$= \frac{0.151} {1.25 \times 10^{ - 5} } \\ = 12600 \: kg/ {m}^{3}$

(3 s.f.)

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3 years ago

6.) 50.0 mol H2O<br> ? molecules

8_murik_8 [283]

<h3>Answer:</h3>

3.01 × 10²⁵ molecules H₂O

<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>

<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>

50.0 mol H₂O

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

Avogadro's Number

<u>Step 3: Convert</u>

<u /> $\displaystyle 50.0 \ mol \ H_2O(\frac{6.022 \cdot 10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O} )$ = 3.011 × 10²⁵ molecules H₂O

<u>Step 4: Check</u>

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

3.011 × 10²⁵ molecules H₂O ≈ 3.01 × 10²⁵ molecules H₂O

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2 years ago

Unlike acceleration and velocity, speed does NOT need to specify

jarptica [38.1K]

Answer:

C) mass.

Explanation:

The speed of a body is given by the relation between the displacement of a body in a given time. It can be considered the greatness that measures how fast a body moves.

Speed analysis is divided into two main topics: average speed and instantaneous speed. It is considered a vector quantity, that is, it has a module (numerical value), a direction (Ex .: vertical, horizontal) and a direction (Ex .: forward, upwards). However, for elementary problems, where there is displacement in only one direction, the so-called one-dimensional movement, it is advisable to treat it as a scalar quantity (with only numerical value).

The mass of an object is not an important factor in determining the speed of that object. However, time, direction and distance are important factors in determining speed.

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3 years ago