if a body is in motion at constant speed in a straight line, what, of any, forces could be acting on it

Which do you think will warm up the plate more quickly?

neonofarm [45]

Answer: B

your welcome Bsbssnsnsmsllqql

3 0

2 years ago

What’s the lowest point of a wave called

ioda

it is called the trough.

6 0

3 years ago

Read 2 more answers

g If 50.0 mL of a 0.75 M acetic acid solution is titrated with 1.0 M sodium hydroxide, what is the pH after 10.0 mL of NaOH have

V125BC [204]

Answer:

pH = 2.66

Explanation:

Acetic Acid + NaOH → Sodium Acetate + H₂O

First we calculate the number of moles of each reactant, using the given volumes and concentrations:

0.75 M Acetic acid * 50.0 mL = 37.5 mmol acetic acid

1.0 M NaOH * 10.0 mL = 10 mmol NaOH

We calculate how many acetic acid moles remain after the reaction:

37.5 mmol - 10 mmol = 27.5 mmol acetic acid

We now calculate the molar concentration of acetic acid after the reaction:

27.5 mmol / (50.0 mL + 10.0 mL) = 0.458 M

Then we calculate [H⁺], using the following formula for weak acid solutions:

[H⁺] = $\sqrt{C*Ka}=\sqrt{0.458M*1.76x10^{-5}}$

[H⁺] = 0.0028

Finally we calculate the pH:

pH = -log[H⁺]

pH = 2.66

8 0

2 years ago

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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What is the Ka of a weak acid (HA) if the initial concentration of weak acid is 4.5 x 10-4 M and the pH is 6.87? (pick one)

rewona [7]

Answer:

Ka = $4.04 \times 10^{-11}$

Explanation:

Initial concentration of weak acid = $4.5 \times 10^{-4}\ M$

pH = 6.87

$pH = -log[H^+]$

$[H^+]=10^{-pH}$

$[H^+]=10^{-6.87}=1.35 \times 10^{-7}\ M$

HA dissociated as:

$HA \leftrightharpoons H^+ + A^{-}$

(0.00045 - x) x x

[HA] at equilibrium = (0.00045 - x) M

x = $1.35 \times 10^{-7}\ M$

$Ka = \frac{[H^+][A^{-}]}{[HA]}$

$Ka = \frac{(1.35 \times 10^{-7})^2}{0.00045 - 0.000000135}$

0.000000135 <<< 0.00045

$Therefore, Ka = \frac{(1.35 \times 10^{-7})^2}{0.00045 } = 4.04 \times 10^{-11}$

5 0

2 years ago