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2 years ago

HALLP ME STUCKKKKK

Chemistry

2 answers:

likoan [24]2 years ago

7 0

Answer:

The average height of the sunflower sprouts at the end of week 3 is 12.0

cm.

The average height of the birch sprouts at the end of week 3 is 7.2

cm.

Explanation:

they showed it on edgu

astra-53 [7]2 years ago

4 0

Answer: Sunflower height-12.0 centimeters

Birch Plant-7.2 centimeters

Explanation:

Its how much they grew.

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A quantity of 85.0 mL of 0.900 M HCl is mixed with 85.0 mL of 0.900 M KOH in a constantpressure calorimeter that has a heat capa

bogdanovich [222]

Explanation:

The given data is as follows.

$V_{1}$ = 85.0 ml, $M_{1}$ = 0.9 M

$V_{2}$ = 85.0 ml, $M_{1}$ = 0.9 M

Hence, number of moles of HCl and KOH will be the same because both the solutions have same volume and molarity.

So, No. of moles = Molarity × Volume

= $0.9 M \times 0.085 L$ (as 1 L = 1000 ml so, 85 ml = 0.085 L)

= 0.076 mol

As 1 mole gives 56.2 kJ/mol of heat of neutralization. Hence, calculate the heat of neutralization given by 0.076 moles as follows.

$56.2 kJ/mol \times 0.076 mol$

= 4.271 kJ

or, = 4271 J (as 1 kJ = 1000 J)

Therefore, heat released = - heat of gained by calorimeter

Since, it is given that density of the solution is similar to the density of water which is 1 g/ml.

Hence, mass of HCl = density × Volume of HCl

= 1.00 g/ml × 85.0 ml

= 85 g

Similarly, mass of KOH = = density × Volume of HCl

= 1.00 g/ml × 85.0 ml

= 85 g

Hence, total mass of the solution = 85 g + 85 g

= 170 g

Also, q = $mC \Delta T$

4271 J = $170 g \times 325 J/^{o}C \times (T_{f} - 18.24)^{o}C$

0.0773 = $T_{f} - 18.24$

$T_{f}$ = $18.317^{o}C$

Thus, we can conclude that final temperature of the mixed solution is $18.317^{o}C$ .

6 0

2 years ago

Classify the following as a type of potential energy or kinetic energy (use the letters K or P)

Zanzabum

K, P, K, K, P, K, K, P, K, P. If it is moving, it is kinetic, if it isn't, it's potential. the sugar one is a little tricky using that method though, because we generally consider this in terms of spacial movement, but sugar holds energy which is later released by your body to allow you to move.the chemical bonds have potential energy because they release energy when broken.

5 0

2 years ago

Read 2 more answers

Chandra forms her question: "What is the effect of soda on plant growth?" What would be a good hypothesis for this question?

ratelena [41]

Soda provides nutritional value that helps plants grow.

Explanation:

I just did this question and that’s what was right.

3 0

2 years ago

A sample of an unknown substance has a mass of 0.158 kg. If 2,510.0 J of heat is required to heat the substance from 32.0°C to 6

Alexxandr [17]

Specific heat capacity is the required amount of heat per unit of mass in order to raise teh temperature by one degree Celsius. It can be calculated from this equation: H = mCΔT where the H is heat required, m is mass of the substance, ΔT is the change in temperature, and C is the specific heat capacity.

H = m<span>CΔT
2501.0 = 0.158 (C) (61.0 - 32.0)

C = 545.8 J/kg</span>·°C

5 0

2 years ago

Consider the reaction between nis2 and o2: 2nis2(s)+5o2(g)→2nio(s)+4so2(g) when 11.2 g of nis2 are allowed to react with 5.43 g

stellarik [79]

M(NiS₂) = 11.2 g.
n(NiS₂) = m(NiS₂) ÷ M(NiS₂).
n(NiS₂) = 11.2 g ÷ 122.8 g/mol.
n(NiS₂) = 0.091 mol.
m(O₂) = 5.43 g.
n(O₂) = 5.43 g ÷ 32 g/mol.
n(O₂) = 0.17 mol; limiting reactant.
From chemical reaction: n(NiS₂) : n(O₂) = 2 : 5.
0.091 mol : n(O₂) = 2 : 5.
n(O₂) = 0.2275 mol, not enough.
n(NiO) = 4.89 g .
n(O₂) : n(NiS) = 5 : 2.
n(NiS) = 0.068 mol.
m(NiS) = 0.068 mol · 74.7 g/mol = 5.08 g.
percent yield = 4.89 g / 5.08 g · 100% = 96.2%.

6 0

2 years ago