Find the number of moles of the indicated species: a) 333 mg of Na2B4O7.10H20
1. Find the number of moles of the indicated species: a) 333 mg of Na2B4O7.10H20
Jawaban:
Penjelasan:
[tex]\text{Na}_2\text{B}_4\text{O}_7.10\text{H}_2\text{O}[/tex]
Mr = 2Na + 4B + 8O + 20H
Mr = 2(23) + 4(11) + 17(16) + 20(1)
Mr = 46 + 44 + 272+ 20
Mr = 382
[tex]n = \frac{m}{Mm}\\n = \frac{333}{382}\\n = 0,87 \times 10^-3 \ \text{mol}[/tex]
2. The total mass of a block of butter and a box of cherries is 384 g. The mass of theblock of butter is twice the mass of the box of cherries. Find the mass of the blockof butter.
draw model: ∆∆∆
384÷ 3 = 128
cherries = 128 g
butter = 2x 128
butter = 256 g_____
semangat belajar....
3. The mass of a bag of rice is 3 times the mass of a bag of fruits. If the mass of the bag of the rice is 15 kg, find the mass of the bag of fruits. (please put the calculation)
Jawaban:
5kg
Penjelasan dengan langkah-langkah:
Mass of bag of rice : 3 = Mass of bag of fruit
15 : 3 = 5
Jawaban:
5 kilograms
Penjelasan dengan langkah-langkah:
15 divided by 3 equal to 5
because the weight of the bag of rice is 3 times the weight of the bag of fruit, so the weight of the bag of fruit is the weight of the bag of rice divided by three
gak tau mau ngomong apa lagi
4. When loades with bricks,a lorry has a mass of 11,600 kg.if the mass of bricks is three times that of the empty lorry, find the mass of the bricks
lorry + bricks = 11,600 kg
if bricks = 3x mass of lorry, then,
lorry : bricks = 1:3
mass of bricks:
3/4 x 11,600 kg = 8,700 kg
5. 23.A watermelon has a mass of 12.78 kg. Its mass is thrice the mass of a papaya. Find thetotal mass of the two fruits.
Jawaban:
mtk atau b inggris sih:)
6. Find the position of the center of mass of the system of the sun and Jupiter. (Since Jupiter is more massive than the rest of the planets combined, this is essentially the position of the center of mass of the solar system.) !
Jawaban:
Artinya : Temukan posisi pusat massa sistem matahari dan Yupiter. (Karena Jupiter lebih masif daripada gabungan planet-planet lainnya, ini pada dasarnya adalah posisi pusat ma
7. 2 tins of paint weigh 13,7 kg. Find the mass of 6 tins of paint.
Jawab:
41.1 kg
Penjelasan dengan langkah-langkah:
2 tins = 13.7 kg
1 tins = 13.7/2 = 6.85 kg
6 tins = 6.85 x 6 = 41.1 kg
8. The mass of a blue vase is 2 times the mass of a red vase. The mass of a gold Vase is 4 times the mass of the blue yase. If the difference in masses between the gold vase and the red vase is 14 kg, find the mass of the blue vase.
Blue vase (B), red vase (R) and gold vase (G)
The mass of a blue vase is 2 times the mass of a red vase.
B = 2R
The mass of a gold Vase is 4 times the mass of the blue vase.
G = 4B
If the difference in masses between the gold vase and the red vase is 14 kg,
G - R = 14
Find the mass of the blue vase.
B = ...
Answer:
B = 2R
R = B/2
G = 4B
G = 4(2R)
= 8R = 8(B/2)
= 4B
G - R = 14
4B - B/2 = 14
Multiply both sides by 2
2(4B - B/2) = 2(14)
8B - B = 28
7B = 28
B = 4
The mass of the blue vase is 4 kg.
9. Mr Lim put durians into 23 baskets. The average mass of the 23 baskets of durians was 10.15 kg.find the mass of the last basket of durians if the average mass of the first 22 baskets of durianswas 9.09 kg.
Jawaban:
you can calculate the below equation
Penjelasan dengan langkah-langkah:
to find the last durian's mass, just substract the total mass of 23 durians with the total mass of the first 22 durians.
The mass of the last durians= 23x10.15-22x9.09
10. 7. There are 6 identical wooden cubes, each of side 5 cm. Their total mass is 525 g. Find (a) the mass per cube, (b) the mass per cm³ of a cube. 8. The cost of laying 12 m² of floor tiles is $270. (a) Find the cost of laying floor tiles per m². (b) Find the cost of laying 20 m² of the floor tiles.
[tex]7.a).the \: mass \: per \: cube \\ \frac{total \: mass}{total \: cubes} = \frac{525 \: g}{6 \: cubes} \\ 87,5 \frac{g}{cube} \\ \\ b).the \: mass \: per \: {cm}^{3} \\ \frac{the \: mass}{volume} = \frac{87,5 \: g}{5 \times 5 \times 5} \\ \frac{87,5 \: g}{125 \: {cm}^{3} } = 0,7 \frac{g}{ {cm}^{3} } \\ \\ \\ 8).the \: cost \: per \: {m}^{2} \\ \frac{total \: cost}{total \: tiles} = \frac{270}{12 \: {m}^{2} }[/tex]
$22,5/m²
b). The cost of 20 m² tiles
22,5/m² × 20 m² = $450
11. The total mass of 12 bottles of juice and 11 bottles of syrup was 30.9 kg. The total mass of 3 bottles of juice and 3 bottles of syrup was 8.1 kg. Find the mass of a bottle of syrup.
Jawaban:
description:
juice=x
syrup=y
so:
12x + 11y = 30.9 kg ×1 12x + 11y = 30.9 kg
3x + 3y = 8.1 kh ×4 12x + 12y = 32.4 kg -
-1y = - 1.5 kg
y = - 1.5/-1
y = 1.5 kg
so,mass of a bottle of syrup = 1.5 kg
Penjelasan dengan langkah-langkah:
hope it helps, thank you, follow me if my answer as right
12. The mass of a fifty-cent coin is 7.29 g. Find the total mass of 96 of these coins.
Jawab:
699,84 g
Penjelasan dengan langkah-langkah:
The mass of a fifty-cent coin is 7,29 g, so the total mass of 96 coins is
96x7,29=699,84 g
13. The average mass of some mangoes is 225 g. There are 8 mangoesaltogether. Find the total mass of all the mangoes.
Jawaban:
1.800 g
Penjelasan dengan langkah-langkah:
Rata-rata 8 mangga : 225 g
total berat mangga (a) / banyaknya benda (b) : 225 g
a / 8 = 225 g
a = 225 g x 8
= 1.800 g
Jadi total massa dari seluruh mangga adalah 1.800 gram
14. Ron divided 207 kg of rice into 3 bags, A, B and C, the ratio of the mass of rice in Bag A to the mass of rice in Bag B was 1 : 2. The ratio of the mass of rice in Bag B to the mass of rice in Bag C was 4 : 3. a. Find the ratio of the mass of rice in Bag A to the mass of rice in Bag B to the mass of rice in Bag C. b. Find the mass of rice in Bag A dengan cara ya!!
Jawaban:
a. 2:4:3
b. 46 kg
Penjelasan:
a. A : B = 1 : 2
B : C = 4 : 3
multiply either equation so that both equations have the same value for B. i choose to multiply the first equation by 2. so,
A : B = 2 : 4
since both ratios have the same value for B, we can merge them together.
A : B : C = 2 : 4 : 3
b. mass A = A/total mass x total mass
since we have the ratio for A and the total mass = 2:(2+4+3),
mass A = 2/9 x 207
= 2 x 23
= 46 kg
15. Find A is 5kg heavier than object B is and the mass of object C is twice the mass of object A . If the total mass of three object is 255kg.Find the mass of Object C
A + B + C = 255 kgs
( B + 5 ) + B + 2 ( B + 5 ) = 55
4B + 15 = 255
4B = 255 - 15
4 B = 240
B = 60
C = 2( B + 5 )
C = 130
16. The mass of a fifty-cent coin is 7.29 g. Find the total mass of 96 of these coins.
The total mass of 96 coins
96 x 7,29 g = 699,84 g
17. The total mass of 12 bottles of juice and 11 bottles of syrup was 30.9 kg. The total mass of 3 bottles of juice and 3 bottles of syrup was 8.1 kg. Find the mass of a bottle of syrup. (In KG)
Jawaban:
1, 5 kg
Penjelasan dengan langkah-langkah:
bottles of juice = x
bottle of syrup = y
12x + 11y = 30.9
3x + 3 y = 8,1 (4)
jadi
12x + 11 y = 30.9
12x + 12y = 32.4
eliminasi
-y = -1.5 kg
y = 1.5 kg
18. 22. Find the mass of one apple in grams.
Jawaban:
60
Penjelasan dengan langkah-langkah:
Apel = A
jeruk = J
Pisang = P
A+J+P = 170
J + A = 130 berat P = 170 - 130 = 40
A + P = 100 berat J = 170 - 100 = 70
A= 170 - 40 - 70 = 60 grams
19. The mean mass of five boys is 62 kg. When the mass of a boy is excluded, the mean mass of the remaining four boys becomes 64 kg. Find the mass of the boy that has been excluded.
Penjelasan dengan langkah-langkah:
Let the mass of the excluded boy be "x".
The mean mass of the five boys is 62 kg, so the total mass of the five boys can be expressed as 5 * 62 = 310 kg.
And, the mean mass of the remaining four boys after excluding the one boy is 64 kg, so the total mass of the remaining four boys can be expressed as 4 * 64 = 256 kg.
So, we have the equation: 310 - x = 256 + x,
Solving for x: x = (310 - 256)/2 = 27 kg.
So, the mass of the excluded boy is 27 kg.
Jawaban:
the answer is 54 kg, sorry for messy handwriting
20. The mass of a one-cents coins is 6.74 g. Find the total mass of 83 of these coins.
gampang kok jawabnya!
6.74 g dan 83 brti 83 gram dari 6.74 atau disebut juga:6.74 - 83
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