All categories

3 years ago

ANSWER THESE 5 MULTPLE CHOICE QUESTIONS!!! I'LL GIVE 30 POINTS AND A BRAINIEST:)

Chemistry

2 answers:

Delvig [45]3 years ago

5 0

1 , mag shells a, d i hope this helped

mestny [16]3 years ago

3 0

Answer: 1, magnesium & mg

2, two energy shells

Explanation:

You might be interested in

PLS HELP ASAP I DONT HAVE TIME

11Alexandr11 [23.1K]

Answer:

An autotroph absorbs sunlight from their stoma and converts this solar energy to chemical energy with their chloroplasts. As you can see, the sun's interaction of matter and energy is vital to sustaining all living things on Earth.

Explanation:

5 0

3 years ago

F a cold object is placed in a warm room, heat will move from the object into the room cold will move from the object into the r

Masja [62]

Cold is the absence of heat! so heat moves into the object from the environment (room) rapidly~ and it slows down by time and water is formed on the surface of the object because of cold and hot air.
I hope this helps cx

5 0

3 years ago

The air bags in cars are inflated when a collision triggers the explosive, highly exothermic decomposition of sodium azide (NaN3

Oksanka [162]

Answer : The mass of $NaN_3$ required is, 166.4 grams.

Explanation :

First we have to calculate the moles of nitrogen gas.

Using ideal gas equation:

$PV=nRT$

where,

P = Pressure of $N_2$ gas = 1.00 atm

V = Volume of $N_2$ gas = 113 L

n = number of moles $N_2$ = ?

R = Gas constant = $0.0821L.atm/mol.K$

T = Temperature of $N_2$ gas = $85^oC=273+85=358K$

Putting values in above equation, we get:

$1.00atm\times 113L=n\times (0.0821L.atm/mol.K)\times 358K$

$n=3.84mol$

Now we have to calculate the moles of sodium azide.

The balanced chemical reaction is,

$2NaN_3(s)\rightarrow 2Na(s)+3N_2(g)$

From the balanced reaction we conclude that

As, 3 mole of $N_2$ produced from 2 mole of $NaN_3$

So, 3.84 moles of $N_2$ produced from $\frac{2}{3}\times 3.84=2.56$ moles of $NaN_3$

Now we have to calculate the mass of $NaN_3$

$\text{ Mass of }NaN_3=\text{ Moles of }NaN_3\times \text{ Molar mass of }NaN_3$

Molar mass of $NaN_3$ = 65 g/mole

$\text{ Mass of }NaN_3=(2.56moles)\times (65g/mole)=166.4g$

Therefore, the mass of $NaN_3$ required is, 166.4 grams.

3 0

3 years ago

For the reaction: h2nnh2 (aq) + h2o(l) ⇌ h2nnh3+(aq) + oh- (aq) determine the conjugate base of the acid?

never [62]

In this reaction, water acts as the base and donates a proton to hydrazine (H2NNH2). Hydrazine becomes protonated: [N2H5]<span>+ And thus hydrazine in this reaction is actually a base. The conjugate base of the acting acid H2O is OH- (hydroxide ion).</span>

4 0

4 years ago

Read 2 more answers

A flame test of a colorless solution gives a bright yellow color. When reacted with AgNO3 a white precipitate forms that dissolv

hichkok12 [17]

Answer:

The compound is Na2CO3

Explanation:

A flame test of a colorless solution gives a bright yellow color. The yellow color shows the presence of Sodium.

NaX + AgNO3 → AgX + NaNO3

When reacted with AgNO3 a white precipitate.

AgX + HNO3 → AgNO3 + H2O + CO2

A white precipitate will be formed when AgNO3 reacts with Sodium Chloride (NaCl) or Sodium carbonate(Na2CO3). (Also NaF, Na3PO4 are possible).

When HCL is added to the unknown solution, bubbles form.

Forming bubbles means that there is formed CO2 (and H20)

Na2X + 2HCl → 2NaCl + H2O + CO2

To form CO2 there is carbon needed

This shows that X is CO3 and the compound is Na2CO3

<u>To control:</u>

Na2CO3 + AgNO3 → Ag2CO3 + NaNO3

⇒Ag2Co3 is the white precipitate formed

This precipitate Ag2CO3 + HNO3 will disolve in AgNO3, CO2 and H2O

When Na2CO3 reacts with HCl there is formed NaCL together with bubbles ( which is CO2 and H2O).

The compound is Na2CO3

3 0

3 years ago