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4 years ago

Select the correct Answers.

Chemistry

2 answers:

Mandarinka [93]4 years ago

8 0

Answer:

3. The temperatures of the two substances equalize.

Explanation:

As two objects at different temperatures are placed in contact, heat is transferred from the warmer to the cooler object until the temperature of the two objects be the same.

The amount of heat that is transferred from the warmer object is equal to the amount of heat that is transferred into the cooler object.

This is in agreement with the law of conservation of energy.
So, the right choice is: 3. The temperatures of the two substances equalize.

Vanyuwa [196]4 years ago

7 0

Answer:

A and C

Explanation:

All temperatures end up the same if placed next to the other, and the heat is going out of the carbon dioxide into the water.

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State the number of solutions for Matrix B. a. No Solution b. One Solution c. Infinitely Many Solutions

NISA [10]

Answer:

C. Infinitely Many Solutions

Explanation:

No solution case : This is the case when all given variables are not equal to any constant, for example: there is one row of zeros in matrix e.g 0=3. matrix B don't have any zero row. So, Not True.

One Solution case: This is the case when all variables are independent variables like if they are equal to some constant. e.g x=1,y=2,z=4 , Matrix B have more than one variable in first row due to which it made equation look like x+y=-5. so matrix B can't have only one solution. So, Not True.

Infinitely Many Solutions case: when there is one or more variables which is not equal to any constant and acting as linearly dependent variable, then that matrix have infinite solutions. Matrix B have that variable which is linearly dependent as show in the attachment solution. So, True.

3 0

4 years ago

Please help ! its urgent!!

ArbitrLikvidat [17]

Answer:

Explanation:

Respiration is the process by which you get energy from food. So energy in food is converted to a form that can be used by the body

5 0

3 years ago

A student working in the laboratory produces 6.81 grams of calcium oxide, CaO, from 20.7 grams of calcium

ozzi

Answer:

Percent yield = 57.8 %

Theoretical yield = 11.781 g

Explanation:

Given data:

Mass of CaO produced = 6.81 g

Mass of CaCO₃ react = 20.7 g

Theoretical yield = ?

Percent yield = ?

Solution:

Chemical equation:

CaCO₃ → CaO + CO₂

Number of moles of CaCO₃ :

Number of moles = mass/molar mass

Number of moles = 20.7 g/ 100.1 g/mol

Number of moles = 0.21 mol

Now we will compare the moles of CaCO₃ with CaO.

CaCO₃ : CaO

1 : 1

0.21 : 0.21

Theoretical yield of CaO:

Mass = number of moles × molar mass

Mass = 0.21 mol × 56.1 g/mol

Mass = 11.781 g

Percent yield:

Percent yield = ( actual yield / theoretical yield ) × 100

Percent yield = (6.81 g/ 11.781 g) × 100

Percent yield = 57.8 %

8 0

3 years ago

Engine size is measured by how much air the cylinders displace. A 1996 Pontiac V8 has an engine size of 316.6 cubic inches. What

inna [77]

The size of this engine in cubic meters is $0.0052 m^{3}$ .

Explanation:

As it is stated that engine size can be measured depending upon the amount of air the cylinders displace, it is also stated that the engine of model Pontiac V8 has a size of 316.6 cubic inches. The problem is to convert the size of engine in cubic meters. We know that 1 inch = 0.0254 m.

Then $1 inch^{3}=(0.0254)^{3} m^{3}$

As here the size of engine is 316.6 cubic inches, then in metres it will be

$316.6 \text { inches }^{3}=316.6 \times(0.0254)^{3} \mathrm{m}^{3}=0.0052 \mathrm{m}^{3}$

Thus, the size of the engine in cubic meters will be $0.0052 m^{3}$ .

3 0

4 years ago

One liter of air contains about 0.21 L of oxygen. When filled, the human lungs hold about 6.0 L of air. How much oxygen is in th

Pie

Simple 6L of air times the .21L of O2 = 1.26

3 0

3 years ago