After moving down a group in the periodic table, the number of valence electrons

A student weighed out a sample of acid powder and found the mass to be 1.42 g. When the solution turned pink, the student read t

aalyn [17]

Answer:

306.6g/mol

Explanation:

To calculate molecular weight you need to know how many grams ou have in a determined amount of moles of substance. As you have the mass of the sample (1.42g), you need to find how many moles are, as follows:

The reaction of the acid HX with the base YOH is:

HX + YOH → H₂O + YX

<em>1 mole of acid reacts per mole of base.</em>

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In a titration, the solution turned pink when moles base = moles acid.

Moles of base that the student added (Using the volume and molarity of the solution) are:

32.48mL = 0.03248L ₓ (0.1426 moles base / L) = 0.004632 moles of base

As the titration is in equivalence point, there are 0.004632 moles of the acid

Molecular weight (Ratio between grams of sample and its moles) is:

1.42g / 0.004632 moles =

5 0

4 years ago

A new metal alloy is found to have a specific heat capacity of 0.260 J/(g⋅∘C). First, 47 g of the new alloy is heated to 180. ∘C

Vlad1618 [11]

Answer:

The final temperature, at the equilibrium is 24.14 °C

Explanation:

Step 1: Data given

specific heat capacity of alloy = 0.260 J/(g°C)

MAss of alloy = 47 grams

Mass of water = 110 grams

Specific heat of water = 4.184 J/g°C

Initial temperature of water = 20.0 °C

Initial temperature of alloy = 180.0 °C

Step 2: Calculate the final temperature at equilibrium

Heat lost = heat gained

Qlost = -Qgained

Q(alloy) =- Q(water)

Q=m*c*ΔT

Q = m(alloy)*c(alloy)*ΔT(alloy) = -m(water) * c(water)* ΔT(water)

⇒with m(alloy) = the mass of alloy = 47.0 grams

⇒with c(alloy) = the specific heat of alloy = 0.260 J/g°C

⇒with ΔT(alloy) = the change of temperature = T2- T1 = T2 - 180 °C

⇒with m(water) = the mass of water = 110 grams

⇒with c(water) = the specific heat of water = 4.184 J/g°C

⇒with ΔT(water) = the change of temperature = T2 - 20.0°C

47.0*0.260 * (T2 - 180.0) = - 110 * 4.184 * (T2 - 20.0)

12.22(T2-180.0) = -460.24(T2- 20)

12.22T2 - 2199.6 = -460.24T2 + 9204.8

472.46T2 = 11404.4

T2 = 24.14 °C

The final temperature, at the equilibrium is 24.14 °C

8 0

3 years ago

I need help with science pls help me

ryzh [129]

Answer:

Explanation:

6. When insulating materials rub against each other, they may become electrically charged .

7. Charging by conduction involves the contact of a charged object to a neutral object.

8. Grounding is the process of removing the excess charge on an object by means of the transfer of electrons between it and another object of substantial size.

9. Grounding is the process of removing the excess charge on an object by means of the transfer of electrons between it and another object of substantial size.

6 0

3 years ago

Which element is used to reduce metal oxides and make pure metals?

Setler [38]

Can vary. Carbon is used quite commonly, and extracts metal oxides, works with zinc, iron, tin, lead and copper.

5 0

3 years ago

The reaction of nitrogen(g) with hydrogen(g) to form ammonia(g) proceeds as follows: N2(g) 3H2(g)2NH3(g) When 6.44 grams of N2(g

Semenov [28]

The enthalpy of the reaction is obtained as 4.876 kJ.

<h3>What is the enthalpy?</h3>

The enthalpy of a reaction is the heat that is absorbed or emitted in a reaction.

Given the reaction; N2(g) + 3H2(g) ⇔2NH3(g);

Number of moles of N2 = 6.44 grams/28 g/mol

= 0.23 moles

If 1 mole of N2 releases 21.2 kJ of energy

0.23 moles of N2 releases 0.23 moles * 21.2 kJ /1 mole

= 4.876 kJ

Learn more about enthalpy:brainly.com/question/13996238?

#SPJ1

3 0

2 years ago