All categories

3 years ago

Look at the graph

Chemistry

1 answer:

Vlad [161]3 years ago

7 0

Answer:

a item dropping

Explanation:

KE is movement and PE is height. As it's falling it gets KE and falls downward giving it more KE and less PE

You might be interested in

Which statement describes what happens to the DNA in the process shown? A. Some of the DNA is destroyed, so each daughter cell h

kolbaska11 [484]

hhjjjbvhjbvb

hhmkn

hjkk

hhjj

7 0

3 years ago

4. Find the pH at each of the following points in the titration of 25 mL of 0.3 M HF with 0.3 M NaOH. The Ka value is 6.6x10-4 a

yawa3891 [41]

Explanation:

Since HF is a weak acid, the use of an ICE table is required to find the pH. The question gives us the concentration of the HF.

HF+H2O⇌H3O++F−HF+H2O⇌H3O++F−

Initial0.3 M-0 M0 MChange- X-+ X+XEquilibrium0.3 - X-X MX M

Writing the information from the ICE Table in Equation form yields

6.6×10−4=x20.3−x6.6×10−4=x20.3−x

Manipulating the equation to get everything on one side yields

0=x2+6.6×10−4x−1.98×10−40=x2+6.6×10−4x−1.98×10−4

Now this information is plugged into the quadratic formula to give

x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)−−−−−−−−−−−−−−−−−−−−−−−−−−−−√2x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)2

The quadratic formula yields that x=0.013745 and x=-0.014405

However we can rule out x=-0.014405 because there cannot be negative concentrations. Therefore to get the pH we plug the concentration of H3O+ into the equation pH=-log(0.013745) and get pH=1.86

6 0

3 years ago

Oxygen always has an oxidation number of -2 unless it is combined with fluorine or found in the compound peroxide. When in the c

Tpy6a [65]

When oxygen is found is peroxide, it has an oxidation number of -1.

The chemical formula of hydrogen peroxide is H2O2. We know that hydrogen always has +1 oxidation state until it forms metal hydrides. So in H2O2, the oxidation state ofhydrogen is +1.

Now, let oxidation state of oxygen be x. So,

2 * (+1) + 2*x = 0

2 + 2x = 0

2x = -2

x = -2 / 2

x = -1

Hence, the oxidation number of oxygen in peroxides is -1

6 0

3 years ago

A 32.8 g iron rod, initially at 22.4 C, is submerged into an unknown mass of water at 63.1 C, in an insulated container. The fin

laila [671]

Answer:

mass water = 32.4 g

Explanation:

specific heat iron = 0.450 J/g°C

specific heat water = 4.18 J/g°C

32.8 x 0.450 ( 59.1 - 22.4) + mass water x 4.18 ( 59.1- 63.1)=0

541.7 - mass water x 16.7 = 0

mass water = 32.4 g

3 0

3 years ago

In which reaction does the oxidation number of hydrogen change? In which reaction does the oxidation number of hydrogen change?

dedylja [7]

Answer: The correct answer is $2Na(s)+2H_2O(l)\rightarrow 2NaOH(aq.)+H_2(g)$

Explanation:

Oxidation number is defined as the number which is given to an atom when it looses or gains electron. When an atom looses electron, it attains a positive oxidation state. When an atom gains electron, it attains a negative oxidation state.

Oxidation state of the atoms in their elemental state is considered as 0. Hydrogen is present as gaseous state.

For the given chemical reactions:

Reaction 1: $2HClO_4(aq.)+CaCO_3(s)\rightarrow Ca(ClO_4)_2(aq.)+H_2O(l)+CO_2 (g)$