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2 years ago

Why is melting a physical property of the wax, but flammability is a chemical property?

1 answer:

6 0

Melting is a physical property and a physical change to wax. We know this because although the wax might melt, it will resolidify into its original form. Flammability, however, is a chemical change because the act of burning involves a chemical reaction between the gases in the air and heat, which cannot be reversed.

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CH4(9) + H2O(g) <> CO(g) + 3 H2(g)

blondinia [14]

Answer:

increasing the temperature decreases the value of the equilibrium constant. Where the forward reaction is endothermic, increasing the temperature increases the value of the equilibrium constant if u increase the temperature, the position of equilibrium will move in such a way as to reduce the temperature again

Explanation:

5 0

2 years ago

A radio wave travels 186,000 miles per second. How many kilometers will the wave travel in one microsecond? (1 mile = 1.61 km)

Komok [63]

1) 1 second = 1000000 microseconds

2) 186000 / 1.61 = 115527.9503 Km

3) We use the equation:
Speed = distance / time

4) rearrange for distance by multiplying both sides by time to get;

Distance = speed x time

5) plug in the values:

Distance = 115527.9503 x 0.000001
= 0.1155279503 Km

6 0

2 years ago

Using standard heats of formation, calculate the standard enthalpy change for the following reaction. 2NH3(g) 3N2O(g)4N2(g) 3H2O

trasher [3.6K]

Answer: $\Delta H^{0} = -879.15 kJ/mol$

Explanation: Heats of formation is the amount of heat necessary to create 1 mol of a compound from its molecular constituents. The basic conditions the substance is formed is at standard conditions: 1 atm and 25°C. Each compound has its own heat of formation per mol of compound (kJ/mol), but to an element is assigned a value of zero.

Standard Enthalpy Change is defined as the heat absorbed or released when a reaction takes place. It can be positive or negative, which means reaction is endothermic or exothermic, respectively.

Enthalpy change is calculated as the difference between the sum of heat formation of products and the sum of heat formation of the reactants:

$\Delta H^{0}=\Sigma H^{0}_{f}_{(products)}-\Sigma H^{0}_{f}_{(reactants)}$

For the reaction

2NH₃ + 3N₂O → 4N₂ + 3H₂O

2(-46.2) + 3(82.05) 4(0) + 3(-241.8)

$\Delta H^{0}=3(-241.8)-[ 2(-46.2)+3(82.05)]$

$\Delta H^{0}=-725.4-153.75$

$\Delta H^{0}=-879.15$

The standard enthalpy change for the reaction is $\Delta H^{0}=-879.15$ kJ

8 0

2 years ago

Which period is the shortest in the long form of the periodic table? Name all the

Andreyy89

Answer:

The first period is the shortest in the long form of periodic table

Explanation:

the long form or the modern periodic table is based on ht modern periodic law. it has 7 periods and 18 groups. this periodic table is widely used by people all over the world. the chemical and physical properties of the elements can be easily identified due to their classification into groups and periods or their position in the periodic table. the first period is the shortest in the long form of periodic table. there are two elements present, they are- hydrogen(H) and helium (He)

8 0

3 years ago

WILL MARK BRAINLY! Which chemical element has the shortest name?

Aleonysh [2.5K]

Answer:

boron I guess

hope this heps

5 0

2 years ago