What are the signs of a chemical reaction

What is one effect of convection currents in the mantle?

Pie

Answer:

D

Explanation:

due yo high energy from the ocean to the earth

4 0

2 years ago

Given the reaction:CO2 + 6 H2O==> C6H12O6 + 6 O2

kari74 [83]

For every 1 mole of C6H12O6, you need 6 moles of water. Multiply the 2.5 moles you are trying to make by the 6 of water you need, and 4) 15 is your answer.

5 0

3 years ago

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Maria is baking cookies. She mixes water, flour, sugar, baking powder, butter and chocolate chips and then measures the mass of

Mrrafil [7]

Answer:

The law of conservation of mass was obeyed since some of the mass evaporated while the cookies were baking.

Explanation:

Maria mixes water, flour, sugar, baking powder, butter and chocolate chips and then measures the mass of her ingredients.

Initial mass of ingredients = 1053 g

Final mass = 845 g

All these information are not of any great help.

Law of conservation of mass states that:

For any system closed to all transfers of matter and energy, the mass of the system can not change with respect to time, as system's mass cannot change, any mass can neither be added nor be removed.

In this process of baking, considering the cookies as our system, they never formed a closed system. Hence were free for evaporation.

During the process of baking, water from dough must have evaporated and mass must have reduced.

Hence, the law of conservation of mass was not obeyed.

8 0

3 years ago

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If a chemical reaction occurs in a direction that has a positive change in entropy thenGroup of answer choicesthe change in enth

mezya [45]

Answer:

The reaction must be spontaneous, the disorder of the system increases.

Explanation:

By the Second Law of Thermodynamics, a positive change in entropy is due to a net input heat, and entropy is a measure of the grade of disorder within the system. The net input heat means that resultant goes to the system from the surroundings.

By the First Law of Thermodynamics, a net input heat is due to a positive change in enthalpy.

The reaction is endothermic and spontaneous (since change in entropy is positive).

6 0

3 years ago

Calculate the number of sodium ions, perchlorate ions, Cl atoms and O atoms in 17.8 g of sodium perchlorate. Enter your answers

Degger [83]

17.8 g of sodium perchlorate contains 8.73 × 10²² Na⁺ ions, 8.73 × 10²² ClO₄⁻ ions, 8.73 × 10²² Cl atoms and 3.49 × 10²³ O atoms.

First, we will convert 17.8 g of NaClO₄ to moles using its molar mass (122.44 g/mol).

$17.8 g \times \frac{1mol}{122.44g} = 0.145 mol$

Next, we will convert 0.145 moles to molecules of NaClO₄ using Avogadro's number; there are 6.02 × 10²³ molecules in 1 mole of molecules.

$0.145 mol \times \frac{6.02 \times 10^{23}molecules }{mol} = 8.73 \times 10^{22}molecules$

NaClO₄ is a strong electrolyte that dissociates according to the following equation.

NaClO₄ ⇒ Na⁺ + ClO₄⁻

The molar ratio of NaClO₄ to Na⁺ is 1:1. The number of Na⁺ in 8.73 × 10²² molecules of NaClO₄ is:

$8.73 \times 10^{22}moleculeNaClO_4 \times \frac{1 ion Na^{+} }{1moleculeNaClO_4} = 8.73 \times 10^{22}ion Na^{+}$

The molar ratio of NaClO₄ to ClO₄⁻ is 1:1. The number of ClO₄⁻ in 8.73 × 10²² molecules of NaClO₄ is:

$8.73 \times 10^{22}moleculeNaClO_4 \times \frac{1 ion ClO_4^{-} }{1moleculeNaClO_4} = 8.73 \times 10^{22}ion ClO_4^{-}$

The molar ratio of ClO₄⁻ to Cl is 1:1. The number of Cl in 8.73 × 10²² ions of ClO₄⁻ is:

$8.73 \times 10^{22}ion ClO_4^{-} \times \frac{1 atomCl }{1ion ClO_4^{-}} = 8.73 \times 10^{22}atom Cl$

The molar ratio of ClO₄⁻ to O is 1:1. The number of O in 8.73 × 10²² ions of ClO₄⁻ is:

$8.73 \times 10^{22}ion ClO_4^{-} \times \frac{4 atomO }{1ion ClO_4^{-}} = 3.49 \times 10^{23}atom O$

17.8 g of sodium perchlorate contains 8.73 × 10²² Na⁺ ions, 8.73 × 10²² ClO₄⁻ ions, 8.73 × 10²² Cl atoms and 3.49 × 10²³ O atoms.

You can learn more Avogadro's number here: brainly.com/question/13302703

8 0

2 years ago