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1 year ago

What does the mass number of an atom represent?.

Chemistry

1 answer:

mamaluj [8]1 year ago

8 0

Answer:

the sum of the numbers of protons and neutrons present in the nucleus of an atom.

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The process of removing or adding electrons is called __________.

nikdorinn [45]

The process of removing or adding electrons is called ionization

5 0

2 years ago

Is the sun typical of these nearby stars

marshall27 [118]

No the sun is the biggest star in the universe.

8 0

2 years ago

Solid carbon (C) can burn in oxygen (O2). Select

babunello [35]

Answer:

OCO

Another way of writing CO₂

Explanation:

A reaction equation has reactants on the left and products on the right.

The reactants are carbon and oxygen. The product is carbon dioxide.

C + O₂ → CO₂

You might see the equation both ways.

C + O₂ → OCO

C + O₂ in the products would mean no reaction has occurred. The problem can solid carbon can burn in oxygen, so a reaction will occur. For no reaction, you would put "NR" in the products.

OCO is the structural way of writing CO₂. Both have one carbon atom (C) and two oxygen atoms (O).

C + 2O is not possible. Oxygen, if alone, has to be at least O₂ because it's a diatomic molecule.

3 0

2 years ago

The acid-dissociation constant for benzoic acid (C6H5COOH) is 6.3×10−5. Calculate the equilibrium concentration of H3O+ in the s

raketka [301]

Answer : The equilibrium concentration of $H_3O^+$ in the solution is, $2.1\times 10^{-3}M$

Explanation :

The dissociation of acid reaction is:

$C_6H_5COOH+H_2O\rightarrow H_3O^++C_6H_5COO^-$

Initial conc. c 0 0

At eqm. c-x x x

Given:

c = $7.0\times 10^{-2}M$

$K_a=6.3\times 10^{-5}$

The expression of dissociation constant of acid is:

$K_a=\frac{[H_3O^+][C_6H_5COO^-]}{[C_6H_5COOH]}$

$K_a=\frac{(x)\times (x)}{(c-x)}$

Now put all the given values in this expression, we get:

$6.3\times 10^{-5}=\frac{(x)\times (x)}{[(7.0\times 10^{-2})-x]}$

$x=2.1\times 10^{-3}M$

Thus, the equilibrium concentration of $H_3O^+$ in the solution is, $2.1\times 10^{-3}M$

4 0

2 years ago

The specific rotation of (S)-2-butanol is +13.5. If 0.119 g of its enantiomer is dissolved in 10.0 mL of ethanol and

larisa86 [58]

Answer:

+15.8°

Explanation:

The formula for the observed rotation (α) of an optically active sample is

α = [α]lc

where

l = the cell path length in decimetres

c = the concentration in units of g/100 mL

[α] = the specific rotation in degrees

1. Convert the concentration to units of g/100 mL

$c = \frac{\text{0.119 g}}{\text{10.0 mL}} \times \frac{10 }{10 } =\frac{\text{1.19 g}}{\text{100 mL}}$

2. Calculate the observed rotation

$\alpha = (+13.3 ^{\circ}) \times 1.19 \times 1 = +15.8^{\circ}$

7 0

2 years ago