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2 years ago

Cho muối X vào dd NaOH, đun nóng, thu được một chất khí làm xanh giấy quỳ ẩm. Chất nào sau đây thỏa mãn tính chất của X?

Chemistry

1 answer:

klasskru [66]2 years ago

4 0

Answer:

A is correct answer.I hope it helps you

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Is the movement of plates to form land masses is called plate tectonics

joja [24]

Yes the movement of land forms is called the movment of plate tectonics. :) plz thnk me

4 0

3 years ago

Consider the reaction:

stich3 [128]

Answer:

$\large \boxed{\text{-851.4 kJ/mol}}$

Explanation:

2Al(s) + Fe₂O₃(s) ⟶ Al₂O₃(s) + 2Fe(s); ΔᵣH = ?

The formula for calculating the enthalpy change of a reaction by using the enthalpies of formation of reactants and products is

$\Delta_{\text{r}}H^{\circ} = \sum \Delta_{\text{f}} H^{\circ} (\text{products}) - \sum\Delta_{\text{f}}H^{\circ} (\text{reactants})$

2Al(s) + Fe₂O₃(s) ⟶ Al₂O₃(s) + 2Fe(s)

ΔfH°/kJ·mol⁻¹: 0 -824.3 -1675.7 0

$\begin{array}{rcl}\Delta_{\text{r}}H^{\circ} & = & [1(-1675.7) + 2(0)] - [2(0) - 1(-824.3)]\\& = & -1675.7 + 824.3\\& = & \textbf{-851.4 kJ/mol}\\\end{array}\\\text{The enthalpy change is } \large \boxed{\textbf{-851.4 kJ/mol}}$

7 0

3 years ago

Which of the following phase changes only occurs in solids possessing vapor pressures above atmospheric pressure and at ambient

GuDViN [60]

Answer: The phase change process in which solids gets converted to gases is sublimation.

Explanation:

For the given options:

Option a: Condensation

It is a type of process in which phase change occurs from gaseous state to liquid state at constant temperature.

$Gas\rightleftharpoons Liquid$

Option b: Melting

It is a type of process in which phase change occurs from solid state to liquid state at constant temperature.

$Solid\rightleftharpoons Liquid$

Option c: Sublimation

It is a type of process in which phase change occurs from solid state to gaseous state without passing through the liquid state at constant temperature.

$Solid\rightleftharpoons Gas$

Option d: Deposition

It is a type of process in which phase change occurs from gaseous state to solid state without passing through the liquid state at constant temperature.

$Gas\rightleftharpoons Solid$

Hence, the phase change process in which solids gets converted to gases is sublimation.

4 0

3 years ago

Type the correct answer in the box.

IgorLugansk [536]

Answer:

a= In scientific notation

6.96000×10⁵ Km

b =In expanded notation

0.00019 mm

Explanation:

Given data:

Radius of sun = 696000 Km

size of bacterial cell = 1.9 ×10⁻⁴ mm

Radius of sun in scientific notation = ?

Size of bacterial cell in expanded notation = ?

Solution:

Scientific notation is the way to express the large value in short form.

The number in scientific notation have two parts.

. The digits (decimal point will place after first digit)

× 10 ( the power which put the decimal point where it should be)

for example the number 6324.4 in scientific notation will be written as = 6.3244 × 10³

Radius of sun:

696000 Km

In scientific notation

6.96000 × 10⁵ Km

The expanded notation is standard notation of writing the numerical values which is normal way. The numbers are written as they are, without the power of 10.

Size of bacterial cell:

1.9 ×10⁻⁴ mm

In expanded notation

1.9/ 10000 = 0.00019 mm

3 0

3 years ago

NEED HELP!!!

Mekhanik [1.2K]

Answer:

b. The shorter the half-life, the more dangerous the radioisotope.

8 0

3 years ago