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3 years ago

Help me plsssssssss Brainliest to correct answer

Chemistry

1 answer:

Elina [12.6K]3 years ago

8 0

It may be unreliable because it might mess something up from the speed.

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i have a crossword thing that i got from school and one of the clues is: If there are two equal and opposite forces on something

cluponka [151]

I would assume the answer is called attractive

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2 years ago

Read 2 more answers

Hydrogen bonding is --

Virty [35]

Hydrogen bonds are a strong attractive force, since they are less stronger than ionic bonds.

4 0

2 years ago

Atoms can be combined in simple, whole number ratios

Anna11 [10]

It’s 71 and 91 to 821

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3 years ago

1. A 5.05 g sample of quartz (SiO2) contains 2.36 g of silicon. What are the percentages of silicon

hammer [34]

Answer: B) 46.7% Si and 53.3% O

Explanation:

To calculate the mass percent of element in a given compound, we use the formula:

$\text{Mass percent of element}=\frac{\text{Mass of element}}{\text{total mass}}\times 100\%$

Mass of quartz $(SiO_2)$ = 5.05 g

Mass of silicon = 2.36 g

Mass of oxygen = Mass of quartz $(SiO_2)$ - mass of silicon = 5.05g - 2.36 g = 2.69 g

$\text{Mass percent of silicon}=\frac{\text{Mass of silicon}}{\text{total mass of quartz}}\times 100=\frac{2.36}{5.05}\times 100=46.7\%$

$\text{Mass percent of oxygen}=\frac{\text{Mass of oxygen}}{\text{total mass of quartz}}\times 100=\frac{2.69}{5.05}\times 100=53.3\%$

Thus the percentages of silicon and oxygen in quartz are B) 46.7% Si and 53.3% O

6 0

2 years ago

Which of the following is not true for an exothermic reaction?

Gennadij [26K]

Answer:

The false statement regarding an exothermic reaction is: A. the products have a higher enthalpy than reactants

Explanation:

An exothermic reaction is a type of chemical reaction that involves the release of energy from the system to the surroundings. Thus increasing the temperature of the surroundings.

In this reaction, the enthalpy or energy of the reactants is greater than the enthalpy or energy of the products. ( $\Delta H_{f} (Products) < \Delta H_{f} (reactants)$ )

As the enthalpy change of a reaction: $\Delta H_{r} = \sum \Delta H_{f} (Products) - \sum \Delta H_{f} (reactants)$

Therefore, the enthalpy change for an exothermic reaction is negative ( $\Delta H_{r} < 0$ )

4 0

3 years ago